TACNEX 1" Wide Straps/Belt Keepers Elastic Military Webbing Holder Tactical Belt Loop Stays Backpack/Harness Strap/Sling Retainer Band Organizers

Strap Keepers! You can get a variety of different ones. All elastic (if you go this round just be mindful of the size like 1” or 1.5”) Tom Bihn sells some fancy schmancy ones You can even get just Velcro straps (think of what you’d use for cable management)