This chain is compatible with Hammerhead 80T gokart with 6.5hp Engine. TrailMaster Mid XRS & TrailMaster Mid XRX. Go Kart Chain details: Master Link Included. 66 Pins. Trailmaster part numbers:7.060.016. Hammerhead part # 7.160.016. This chain does NOT work for the Mudhead 208R or Mid XRX with Reverse.