This cover prevents the safety pins from coming off and prevents them from falling off. Just attach the main unit cover to the fastener part of the safety pins, making it easy to install. Size M is recommended for cans of 2.6 to 3.1 inches (65 to 80 mm). Product Size: Approx. W 0.2 x H 0.4 x D 0.2 inches (5 x 10 x 4 mm); Quantity: 5 pieces; Color: Transparent; *Not compatible with hook pins.