Meaning that the air flow cannot be blocked, it needs to be open.Milton's description:Extended reach dual head straight foot air chuck for inner duals has is designed and manufactured to exacting standards. The extra reach of 12" is great for inflating the inner duals. Sealing type chuck is closed and is for use on an airline. With a cushioned grip handle, this air chuck also locks onto tire valve thread. Not for use with an inflator gage. Maximum pressure of 150 PSI.
I think the 400P-RVS may work better for you. https://www.rvupgradestore.com/Viair-400P-RVS-Automatic-Portable-Tire-Compresso