This attachment is fully compatible with our G4 Zero gap bench, and unlocks more workout potential by converting your current bench into to a fully flat-incline-decline (FID) bench. This sturdy attachment is constructed with 11 gauge steel, and is easily removable, so you are able to simply slide it on and off when you want to do decline exercises, like decline sit-ups and decline chest presses. You simply slide the leg roller feature to your current bench, easily adjust to your desired angle, and get to work.