Arrow 71863AKN Thunder Dark Aluminium Slip-On Muffler w/Carbon End Cap for Yamaha YZF R6 17-21Arrow Thunder Slip On Exhaust Yamaha R6 More and more modern motorcycles are designed with compact mufflers that compliment their overall style and aggressive good looks. Arrow's goal was to maintain this aesthetic while further reducing overall weight and dimensions. Compared to most stock mufflers, the Arrow Thunder Exhaust features a compact and lightweight design and yet still packs a big punch. Arrows signature diamond shade design has not been