Deck Fill Replacement Cap Chain This Attwood Replacement Cap and Chain is made for Attwood deck fills. The flush cap is slotted for a separate key and features an O-ring that seals the cap watertight. – Features: Cap is attached by a stainless steel beaded chain Specifications Cap and Chain are Fitted for This Deck Fill Size: 3-1/4 inch Fill Neck Length 1-7/8 inch installation hole size 3-inch flange size Fits 1-1/2 inch I.D. Hose *Key sold separately