Not sure if the dimensions for comparison but an Enola Gaye flash grenade (this one: http://www.enolagaye.com/thunderflash/flash-grenade/ ) fits quite nicely into the WAS 40mm grenade pouch. The bottom of the pouch is elasticated and the lid is adjustable via velcro down the back. It also has press studs in the lid so it's a bit more secure than a standard velcro clsoing pouch (I recently bought one of these: http://www.uktactical.com/p-7540-warrior-triple-40mm-grenade-coyote-tan.aspx )