Say goodbye to that plastic “fake rock” look forever with realistic Atlantic Water Gardens Rock Lids. Molded from real stones, the sturdy fiberglass construction, authentic textures and incredibly real finishes set these Rock Lids apart from other faux stones. Find the perfect fit for every application. No one will ever know it’s not real! RL30 models fit the PS3900 skimmer and PV1800 or PV2300 pump vaults. Cover rocks measure 24"L x 24"W x 5"H.