Plastic Bulkhead Fitting Straight Choose Size Quantity Flat Shipping for as Many as you Order Description This listing is for1pcbulkhead fitting. Please be sure to check out the measurements in the picture and choose the correct size that fits you. Barb connects to hose internal diameter: 4mm approximately 5 32 If you require large quantity you can contact us for a custom quote. We offer a variety of plastic fittings. Please check out our other listings for details. SHIPPING.