30 provides a ramped portion of disc 10 which may be of increased rigidity to facilitate the disc 10 negotiating obstacles often projecting from interior pool surfaces pins or stops 32 which may be integrally formed with and project upward from the reinforced area 28 of disc 10 cooperate with portions of a footpad or other component to inhibit misorientation of disc 10 in use lip 30 forms the leading edge of disc 10 as it and associated equipment move throughout a pool or other vessel enabling the disc 10 to ride over objects encountered therein openings 34 through disc 10 enable fluid to pass between upper and lower surfaces 18 and 22 of disc 10 when in use maintaining a boundary fluid layer between the lower surface 22 of disc 10 and the adjacent surface of the pool or other structure to be cleaned shown in fig3 4 is ramp 38 projecting from lower surface 22 of disc 10 and positioned concentrically about central aperture 14 ramp 38 promotes a smooth transition between lower surface 22 and the bottom of a footpad or other component received by central aperture 14 facilitating unobstructed movement of a swimming pool cleaner associated with the footpad fig3 similarly discloses radius 42 existing between lip 30 and lower surface 22 of disc 10 providing a smooth transition therebetween and as noted above an inclined surface or ramp for negotiating obstacles in an embodiment of the invention consistent with fig1 5 flutes 26 are positioned.