Anyone know what this is?

[fatboytank320]

I've been trying to figure out what the name of this is, It came on my 1987 Honda trx250x, it bolts to my swingarm bolt and my chain runs through it, I've kicked the chain off a couple times and it doesnt let it get stuck in the rearend...Cant say the same about the front though, my chain slapped into it the other day and busted the left case cover...But here's a pic, looking for what it's called, Any help is much appreciated..Thanks...

http://img228.imageshack.us/img228/3337/s7301149s.th.jpg (http://img228.imageshack.us/i/s7301149s.jpg/)

http://img228.imageshack.us/img228/2836/s7301148.th.jpg (http://img228.imageshack.us/i/s7301148.jpg/)

http://img228.imageshack.us/img228/1102/s7301146.th.jpg (http://img228.imageshack.us/i/s7301146.jpg/)

[Rich250RRacer]

That is an Amplink.

[fatboytank320]

Thanks man, was starting to wonder about it...After reading some stuff on it Im glad I took it off lol...