Forged steel, hot dipped, galvanized. Open-throat design, wide bow, screw pin shacklet requires no tools to assemble. Slip screwdriver blade or hand punch through pin/eye and tighten. Meets Federal Specification RRC-271B, Type IV, Class 1. No./Body Dia.ins. 3/16: 7/18" Inside Lngth, 3/8" Width Between Eyes. No./Body Dia. Ins. 1/4IN: 1-1/8" Inside Lngth, 15/32" Width Between Eyes. No./Body Dia. Ins. 5/16: 1-1/4" Inside Lngth, 17/32" Width Between Eyes. No./Body Dia. Ins. 3/8: 1-7/16" Inside Lngth,21/32" Width Between Eyes. No./Body Dia. Ins. 1/2: 1-15/16" Inside Lngth, 13/16" Width Between Eyes. No./Body Dia. Ins. 5/8: 2-1/2" Inside Lngth, 1-1/16" Width Between Eyes. No./Body Dia. Ins. 3/4: 3" Inside Lngth, 1-1/4" Width Between Eyes. No./Body Dia. Ins. 7/8: 3-1/4" Inside Lngth, 1-7/16" Width Between Eyes. No./Body Dia. Ins. 1: 3-3/4" Inside Lngth, 1-11/16" Width Between Eyes.