This is a set of replacement shocks Part Number 10580 for Bowflex Treadclimbers models TC-1000, TC-3000, and TC-5000 version one Used on the following Models Listed Below.  

Bowflex-

TC 6000

TC1000 TreadClimber

TC3000 Version 1

TC5000 Treadclimber 2004 - 2007 Version 1

TC5000 Treadclimber After 2007 Version 2

TC5300 Treadclimber

To determine which version your machine is, go to the front of the machine and unlock your treadles. Push down on one of the treadles to it's lowest position. If the treadle raises back to the resting position and the opposit treadle does nothing, you have the version 2. If the treadle stays at the lowest position and the opposite treadle raises, then you have the version 1 treadclimber.