I really like the rsi stick on heaters with the rsi grips. My mtn max has stick on heaters and the 7" rsi grips. They are super sticky, you practically don't have to hold on when cruising down the trail. I'm re-doing the bars on my indy sks right now and I bought the 8" grips and shortened them. They are a larger diameter which I thought will be more comfortable for long trail rides. I found the stock Polaris stick on heaters are reuse able and the glue sheets are available on eBay. I did find with the mtn max the aluminum bars need the heaters turned up more because aluminum doesn't hold the heat like steel. On the Indy once they warm up low is more than enough most of the time to keep my hands warm.