Instasoft Polyurethane Acoustic insulation board (L)1.2m (W)0.6m (T)40mm, Pack of 6 | DIY at B&Q
The Best Foam for Soundproofing Applications - Intec Foams
Acoustic Panel, High Density Flame Retardant PU Sound Dampening Foam Panel for Recording Studio 50 X 50 X 5cm / 19.7 X 2in : Amazon.co.uk: Musical Instruments & DJ