in this regard it will be observed that the snap ring 58 simply restrains the lens 30 against separation from the lamp housing 20 and does not exert an axial clamping force on the lens similarly the seal ring 96 is effective to seal the mounting box 22 to the clamp ring 66 simply by assemblying the box and ring and without the necessity or precisely coaxially aligning the box and ring or applying an axial clamping force between the box and ring this is an advantage if the shape or condition of the pool wall 16 is such as to preclude effective sealing contact of the seal ring 96 with the wall and or precise coaxial alignment of the mounting box and clamp ring when the clamp ring seal 94 is clamped against the inner surface of the wall under these conditions the seal ring 96 will still seal the mounting box 22 to the clamp ring 66 to prevent water leakage from the pool to the surrounding soil electrical power is fed to the lamp housing 20 thru an electrical cable 100 this cable extends to the lamp housing mounting box 22 thru a tubular electrical conduit 102 the mounting box end of this conduit is threaded in a coupling 104 secured to rear end of the mounting box shell 64 as will be described presently this coupling is uniquely constructed in accordance with this invention for adjustment to accommodate a range of orientations of the conduit 102 relative to.