tensioner used on Front runner

[XLexusTech]

Hi Anyone know what the part number is for the LS version of the Vintage air front runner?
It's not listed on the sight only the covers are. I called support and they told me the reason the belt might be jumping off track is possibly due to a to a bent tensioner. They gave me another thing to try but just i case I want to have one on hand. I want to buy a replacement and they appear to be OEM GM.