Open/Closed Indicator Cap for Gas Valve Cylinder Tank. Improves Efficiency and Shop Safety. Easy to View Cylinder Valve Indicator Snap & Twist Mechanism (Snaps onto welding tank valve) One size fits all: 5, 6, 8 lobe valve knobs. Smooth operation from integratedball bearing design. (Do not need a strong hand to turn) Single Color: Valve is CLOSED (Left) Multi Color: Valve is OPENED (Right) Note: Due to tolerances and variation on knobs the indicator cap may feel lose on the valve, if so, simply place some tape on the side of the valve then place the indicator cap back on the valve. Color shades may vary due to filament availability. See it on YouTube: https://youtu.be/zlWxg5taA2s?si=VV2NM1a3sFG0