Mesa Sling Attachment for Remington Shotguns, Loop or Slot
Amazon.com : Hunting Explorer Gocher Quick Detachable Sling Swivel Cap Set with 1" Quick Release Tri-Lock Swivels Adapter for REM 870 12GA S8002 : Sports & Outdoors
UNCLE MIKE'S 18002 Sling Swivel Cap Set, Quick Detachable, Steel, Black, For: Remington 870 Express 12 ga Shotguns D&B Supply
Amazon.com : Remington 870 Express Shotgun Ammo Sling (25 Shells) - Made in U.S.A. : Gun Slings : Sports & Outdoors
DIY Shotgun Swivel Sling Installation - YouTube
Uncle Mike's Tactical Shotgun Sling Sling Swivel Nylon Black