Push on valve cap for CGA 540 valve without tear tab.  These caps simply push on for easy installation. The valve will stay clean and free of contamination and debris.  These caps are available in green, black and clear. 
For green, see part number ACM 208. For black, see part number ACM 423. This cap will also fit the CGA 540 outlet on Valve Integrated Pressure Regulator Units (VIPR) such as the Walk O2 Bout cylinder.

There are 500 caps per bag.