NXT™ LEVEL PLUS is a high quality, cement-based, free-flowing underlayment for use in leveling interior substrates. Rapid setting formula produces a flat, smooth and hard surface for the installation of finished flooring. NXT LEVEL PLUS can be placed from 1/8'-1 1/4" (3'-32 mm) in a single lift (consult LATICRETE Technical Services for pea gravel extension installation guidelines).