Muc-Off Stealth Tubeless Puncture Plugs Tire Repair Kit – Bar-End Mount Black Pair. When a puncture strikes and its just too big and gnarly to seal the Muc-Off Stealth Tubeless Puncture Plug is the ultimate backup tool which is cleverly stored inside your bar ends. The expanding silica plugs (which are included) cover most MTB road and gravel handlebar sizes and the premium CNC Machined Aluminum bar ends are available in many anodized colors to match your ride. Each lightweight and durable set contains everything you need to get back riding when youre stuck battling a hole thats just not sealing.