Clear anodized tubes have a machined wrench flat on one end for ease of adjustment. Tubes have .156" wall thickness and are available in two diameters with a variety of lengths. The 56400 Series tubes are 7/8" diameter and both ends are tapped 5/8", one RH and one LH. The 56500 Series tubes are 1" diameter and both ends are tapped 3/4", one RH and one LH. 6061-T6 material.