This Locking Ball Foot Chuck is a combination of a standard ball foot air chuck with an attached steel clip for holding the chuck in place on the valve stem during air filling operations. The chuck is for direct air line use which means that it comes equipped with a built-in shutoff valve and is not suitable for use with inflator or pressure gauges. It has a maximum pressure rating of 150 lbs. per square inch (psi) and a 1/4 in. female National Pipe Thread Taper (NPT) connection. This air chuck is suitable for a wide range of general commercial and industrial air filling applications.