Nitrous Oxide System - NOS Super Hi-Flo Nitrous Bottle Valve with Blue Face Gauge for 5 lb. and Larger NOS Bottles (16137NOS)NOS Hi Flo and Super Hi Flo nitrous bottle valves are by far some of the best bottle valves available. By using high quality manufacturing processes and materials, you are sure to get a dependable and long lasting product from NOS. NOS Nitrous Bottle Valves have a large outlet port, o ring seal and large internal ports for exceptional flow capabilities. The Hi Flow valves can support 400+ HP while Super Hi Flo can support 500+ HP. New Hi Flow valves