Locknuts are all steel for greater mechanical hold. Sealing ring maintains liquid-tight seal in a threadless opening. Smooth-ended grounding ferrules can be removed easily without distortion. Patented split gland ring slips on quickly even if conduit end is not cut squarely. Heavy-duty nuts are 3/8" to 1" steel or 1-1/4" to 4" malleable iron continuous thread to prevent seepage.