When a puncture strikes just too big and gnarly to seal, the Muc-Off Stealth Tubeless Puncture Plug ultimate backup tool that's cleverly stored inside your bar ends! A ride-saving tool that-s hidden inside end of the handlebars Features - CNC Machined from 6061 Aluminum - Expanding plug fits most MTB, Gravel & Road Handlebar, over 17mm I.D. - Supplied with 17mm, 19mm and 21mm plugs to fit different bar diameters - Screws into bars using a just a 4mm Allen key - Plugs and repairs multiple holes that won-t seal with just sealant - Includes puncture plug and knife tool