The XDEEP Cargo Pocket is a decent size accessory pocket big enough for a spare mask or dSMB. Two modified trigliders on the back hold the pocket in position on a 2" webbing strap. The main section has a zippered closure with some daisy chain webbing and a small steel D-Ring for anchor points inside.
A small Velcro pocket on the front for smaller accessories and a large Steel D-Ring on the outside for quick attachment.
Dimensions : 221 x 144 x 90mm