An end piece for operatively engaging a head assembly, the head assembly comprising one or more valves, for the treatment and control of fluid passing through the head assembly, said end piece comprising: A. an end piece wall; B. an inlet fitting having a cam surface, said inlet fitting having a longitudinal axis; and C. an outlet fitting; and D. a protrusion having a longitudinal axis; Wherein said inlet fitting, said outlet fitting, and said protrusion extend from said end piece wall, wherein said protrusion is positioned between said inlet and said outlet fittings, wherein the distance from said longitudinal axis of said inlet to said longitudinal axis of said outlet is less than the distance from said longitudinal axis of said inlet to said longitudinal axis of said protrusion, and wherein the distance from said inlet to said longitudinal axis of said protrusion is greater than the distance from said longitudinal axis of said outlet to said longitudinal axis of said protrusion, wherein the distance from said longitudinal axis of said inlet to said longitudinal axis of said outlet is about 2 cm, and wherein the distance from said inlet to said longitudinal axis of said protrusion is about 2 cm, and wherein the distance from said longitudinal axis of said outlet to said longitudinal axis of said protrusion is about 2 cm, and wherein at least a portion of said cam surface is vectored from said longitudinal axis of said inlet fitting. view more

A unit for use in the treatment of fluid, said unit comprising: A. An end piece, said end piece comprising: i. An end piece wall; ii. An inlet fitting having a cam surface distal a sealing surface for actuating an inlet valve, said inlet fitting having a longitudinal axis, said inlet valve having a follower; iii. An outlet fitting for actuating an outlet valve, said outlet fitting having a sealing surface and a longitudinal axis; and iv. A protrusion for actuating a bypass valve; Wherein said inlet fitting and said outlet fitting extend from said end piece wall, and wherein a portion of said cam surface of said inlet fitting is vectored from at least one of said longitudinal axis of said inlet fitting and said longitudinal axis of said outlet fitting; and B. A head assembly, said assembly comprising: i. An inlet receiving port housing for receiving said inlet fitting, said inlet receiving port housing containing at least a portion of said following of said inlet valve; ii. An outlet receiving port housing for receiving said outlet fitting; and iii. A bypass passageway housing which contains said bypass valve, wherein said bypass housing is so arranged to receive said protrusion and said bypass valve is actuated by said protrusion; Wherein said inlet and outlet receiving port housings are so arranged to receive said inlet and outlet fittings, respectively, and said inlet and outlet sealing surfaces seal between said inlet and outlet fittings and said inlet and outlet receiving port housings, respectively, and said follower of said inlet valve is actuated by said cam surface. view more

The unit of claim 2, wherein said protrusion is positioned between said inlet and said outlet fittings.

A cartridge for operatively engaging a head assembly, the head assembly comprising one or more valves, for the treating and control of fluid passing through the head assembly, said cartridge comprising: A. An end piece, said end piece comprising: iv. an end piece wall; v. an inlet fitting having a cam surface, said inlet fitting having a longitudinal axis; vi. an outlet fitting having a cam surface, said outlet fitting having a longitudinal axis; and vii. a protrusion having a longitudinal axis and positioned between said inlet fitting and said outlet fitting; Wherein said inlet fitting, said outlet fitting, and said protrusion extend from said end piece wall; and B. A cartridge housing having a first end, a closed second end, and a longitudinal axis extending therebetween; Wherein said end piece wall is connected to said first end of said cartridge housing, and wherein a portion of said cam surface of said inlet fitting is vectored from at least one of said longitudinal axis of said inlet fitting, said longitudinal axis of said outlet fitting, and said longitudinal axis of said cartridge housing, and wherein a portion of said cam surface or said outlet fitting is vectored from at least one of said longitudinal axis of said inlet fitting, said longitudinal axis of said outlet fitting, and said longitudinal axis of said, cartridge housing. view more

A filter unit comprising: a body portion having a proximal end and a distal end; and an engagement protrusion extending from the proximal end of the body portion, the engagement protrusion having a cross-section with only one axis of symmetry such that a cross-section of the engagement protrusion has a generally egg-shaped configuration, and a laterally extending key member disposed on the body portion. view more

The filter unit of claim 1, further comprising: a first engagement surface traversing at least part of the body portion.

The filter unit of claim 2, further comprising: a second engagement surface traversing at least part of the body portion opposite the first engagement surface.

The filter unit of claim 3, wherein the first and second engagement surfaces are recessed.

A unit for engagement with a water filter system comprising: an engagement protrusion extending from a proximal body portion, wherein the engagement protrusion is configured for selective rotational engagement in a complementary receiver in a filter head assembly, wherein the selective rotational engagement of the engagement protrusion with the complementary receiver places the filter head assembly in selective communication with an interior of the proximal body portion; at least one engagement surface traversing around at least part of the proximal body portion at an angle, the at least one engagement surface configured to cooperate with the complementary receiver in the filter head assembly to define the selective rotational engagement; and at least one seal member disposed on a sidewall of the engagement protrusion, wherein a cross section of the at least one seal member taken at an angle perpendicular to a longitudinal axis of the engagement protrusion and through the sidewall at the at least one seal member includes only one axis of symmetry. view more

The unit of claim 1, wherein the proximal body portion is configured to receive a water filter, and wherein the water filter includes a filtering media.

The unit of claim 1, wherein the interior of the proximal body portion is configured to receive a water filter.

A filter unit comprising: a filtering media; a body portion; an engagement protrusion extending from the body portion and comprising a containment seal, wherein at least one cross section of the engagement protrusion at a location of the containment seal, taken perpendicular to a central longitudinal axis of the body portion, includes an egg-shaped outer perimeter having a single axis of symmetry, and wherein the containment seal acts as a barrier that prevents filtered water from leaking around the body portion during use; at least one engagement surface traversing around at least part of the body portion, the at least one engagement surface having a linear movement section for linear movement of the body portion, wherein the linear movement section transitions to a rotational movement section for rotational movement of the body portion, wherein the rotational movement section is angled from the linear movement section; and a water inlet path and a water outlet path extending through a portion of the engagement protrusion defined by the at least one cross section. view more

The filter unit ofclaim 1, further comprising: a cross-contamination seal configured to keep incoming unfiltered water entering the water inlet path from cross-contaminating with filtered water leaving the water outlet path.

The filter unit ofclaim 1, further comprising: a plurality of grasping cutouts defined within the body portion proximate a distal end of the body portion.

The filter unit ofclaim 1, wherein the rotational movement section of the engagement surface extends along a plane that is substantially perpendicular to the linear movement section of the engagement surface.

The filter unit ofclaim 1, wherein the water outlet path at the at least one cross section is positioned in alignment with the central longitudinal axis of the body portion.

The filter unit ofclaim 1, wherein the water inlet path and the water outlet path at the at least one cross section are in alignment with the single axis of symmetry of the outer perimeter.