WAC'EM Steel SlipCam Hybrid 4-Blade (100 grain) has a Four-Blade Expandable Head. The penetrator tip is Pressed-In Stainless Steel with a Precision Machined Steel Ferrule. It uses . 030" thick fixed blades with a fixed cutting diameter of 1 1/8", 1 5/8 expandable cutting diameter for a total cutting diameter of 2 ¾". This has a O-Ring retention system.