A must have for the AR15/M16 owner who has Zombie problems! The Gen Z Non-rotate Trigger/Hammer Pins are the same pins as the standard Gen 2, but have been Dura-coated Zombie Green. As with the Gen 2 pins, these are the Strongest pins that can be produced and were designed to withstand the high impact of full and semi-auto 9mm, .223mm, and 7.62mm suppressed weapons. The pins are made from high quality stainless steel. An absolute must have for all M16 owners. they will also protect your AR15 from rotation and pins walking. This kit also includes the installation tool, two allen wrenches. No modification to the receiver. The Gen Z is only available with the .154 diameter pins.