Shields Vac Extra Heavy Duty/FDA White multi purpose, extra heavy, smooth walled, vinyl hose for boat and marine sanitation systems. Excellent for critical bilge, drain, scupper line, and potable water fill applications. FDA approved, with low water absorption compounds that resist odor permeation and toilet chemicals. Reinforced with hard vinyl helix. When used below the water line use double clamps and sealing compound. Various internal diameters available. The most widely used hose for all toilet output systems is the 1-1/2 inch inside diameter hose since it has a 4 inch bend radius and 28 VAC rating. All sizes are sold in full rolls of 50 feet except the 5/8 and 1-1/2 inch sizes which are sold in 10 foot increments.