The set includes the counterweight consisting of two half shells and two Delrin adapters for the 1.8in and the 1.5in center post. The Delrin adapters make it possible to mount the counterweight on both the outer 1.8in post and the 1.5in telescoping inner post. The Counterweight is made of stainless steel. Weight: 800gr / 1.77lb Note: The Counterweight Rings can only be used with the artemis and the TRINITY.