This is a NEW seatpost shim.  It is used to make your 25.4mm seatpost fit into your oversized seat tube.  It's really simple:
You have a 25.4mm seatpost (suspension or standard), but you have a frame with a 31.6 mm ID seat tube.  You put this shim/spacer in your seat tube and voila!  Your 25.4mm seatpost will fit precisely in your 31.6mm ID seat tube.
Wondering what size seat tube ID you have?  Often your old seatpost will have it stamped on it, near the bottom. 

Features:
* ID is 25.4mm, thickness is 6.2mm, OD is 31.6mm
* Fits 25.4mm seatposts and 31.6mm ID seat tubes (your frame)
* 60mm long
* Color:  Black
* 6061 Aluminum
* Anodized finish
* Size info printed right on shim
* Weighs about 43g