Aquascape® Pondless® 49001 Waterfall Vault Extension. The Aquascape Pondless® Waterfall Vault Extension increases the height of the Aquascape Pondless® Waterfall Vault for applications with larger pumps or using the AquaBlox® Large Water Storage Modules. The extension is designed to slide directly onto the Pondless® Waterfall Vault. Its durable, rotationally molded, rounded, polyethylene shape maximizes the structural strength of the extension. The extension measures 9″ tall.