The Danco 3-Piece Repair Kit for Moen Faucets helps restore a leaky faucet. Replacing the o-rings will help eliminate leaks around the base of the spout. This kit is ideal for single-handle faucets and will create a better seal and help prevent water leaks. aucets usually have one or more o-rings that prevent water from leaking out around the spout. Replacing worn-out o-rings is an inexpensive alternative to replacing the entire faucet fixture. Stopping the leak saves both water and energy. This o-ring assortment contains 2 sizes of o-rings.