Molded in Marelon® for lifetime durability, Forespar® Deck fills are available in two color-coded models. Each clearly marked for use with either water or waste. (Fuel deck fills no longer available.) Easy-open cap is fitted with nylon retainer cord and rubber 'O'-ring to ensure a safe and efficient seal. Suitable for 1-1/2" (38.10mm) I.D. hose. Deck flange is 4" (101.60mm) diameter. Cutout: 2-1/8" (53.97mm). Hose barb length: 3" (76.20mm).