Sound deadening is made of a butyl rubber material which lowers the frequency of vibrations and thus make them quieter. Vibrating metal from the movement of the van is largest source of noise while driving. This is applied to the walls of your van before you insert the insulation.
This product is sold in 20 sq. ft batches
SPRINTER 144 WB // 80 SQ. FEET
FORD TRANSIT 148 WB // 80 SQ. FEET
PRO MASTER 159 WB // 80 SQ. FEET
SPRINTER 170 WB // 100 SQ. FEET
SPRINTER 170 WB EXTENDED // 100 SQ. FEET