The Roberts Black Jack 2-in-1 Underlayment is designed for use under floated laminate, bamboo and engineered wood floors and is ideal for many types of subflooring. Black Jack is engineered as a superior grade, 2-in-1 underlayment with a 2.5 mm thick foam layer that provides optimal cuHDPEoning and sound HENAN OKAYorption, as well as a closed cell foam