The best deal is to be had with R + G grips: http://www.amazon.co.uk/R-G-Heated-M.../dp/B005FU89QM for about �35
They got a decent write-up from RiDE magazine, but as John said, the controller is the thing that will fail first.
You can probably find them cheaper at the Bike show this weekend?


I bought the Symtec ones for around �45, which are like underfloor heating for your existing grips.
These are fantastic, easy to fit (full instructions included) and REALLY warm.

Fitting thread here : http://www.xt660.com/showpost.php?p=194039&postcount=10

Heated grips + Muffs = Summer gloves all year round!

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Bike: 2013 XT660Z, TKC70 tyres

Mods:
Barkbusters, Scottoiler, DIY Tail Mod, DNA Stage 3, Power Commander V & O2 Eliminator, Exan X-Black Stainless exhaust, Tool tube, Ohlins linear front fork springs, Nitron rear shock, JT front and Supersprox rear sprockets, D.I.D. VX 520 chain, Adventure Spec bashplate, DIY USB Outlet, DIY chain guide, Kev's Throttle mod

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