The Weapons Armorer Sully 870 Ejector system is designed to be installed using 2 screws. The screw design allows for much easier installation, with no special tools required. Simply align the Sully Ejector and Spring, and screw it into place with a few drops of thread locker on the screws.The Sully 870 Ejector system is designed so the spring is tucked under the ejector against the receiver. The ejector is thicker on the front end, which gives greater strength to support the barrel. This design also makes the ejector spring stronger, and eliminates the ejector spring being damaged or torn loose from a rivet. The screw design eliminates the need of having to refinish the receiver. There is no having to grind rivets flush and refinish and re-blue or parkerize the receiver. Note: Fits 12gauge 2-3/4" and 3" Magnum Right Hand Shotguns (Right Side Ejection Port).