PRODUCT FEATURES Bulkhead Fittings External Thread and nut are left hand threads. Internal thread is FPT. For use with tanks having a wall thickness of 1/16" to 1/2". Material - Body and Nut are Polypropylene (P) Friction washer is Polyethylene, sealing washer is EPDM. Polyethylene used in manufacturing are FDA approved grades. Reviews FEATURED PRODUCTS Polypropylene Nipple $1.22 Choose Options Polypropylene Tee 1/2" $5.42 Add to Cart Polypropylene Straight Hose Mender Starting at $1.19 Choose Options Polypropylene Check Valve $14.03 Add to Cart