The GAP STOPPER from Black Diamond is a bouldering accessory.

This versatile padding accessory has been designed to fill gaps, cover blocks and slabs, or be used as a seated starter mat. Thanks to its 4-fold design and numerous side handles, it's easy to transport from one block to another. Its large surface area provides cushioning for landings in the event of a nasty fall. One of the corners also has a mini carpet panel for cleaning your slippers before you start climbing.

This model features ¾" closed-cell foam with a ripstop polyester exterior.