Skimmer to be fitted in the wall of the pond, removes floating waste. Size 1½" female thread. - Internal dimensions flange model A = 209 x 144mm - Internal dimensions flange model B = 372 x 155 mm - Internal dimensions model C = 149 x 142 mm - Internal dimensions model D = 295 x 124 mm D G E Covert a small skimmer into a wide mouth skimmer with this mounting kit (D). Kit comes with adaptor, rubber seal, flange and screws. PE Gatekeeper grid. Restricts fish from entering the skimmer. Size grid normal skimmer: 210 x 205 x 8mm. Size grid wide mouth skimmer: 360 x 195 x 8mm.