TwinRail Courier Berlin HC Hard Compound Street/Fixie Twin ridge, wrap tread Rear tyre.Extra Puncture Protection added on request of the street riders and couriers of Berlin city.Black700x24 or 29Safety note: Hard compound provides increased wear resistance... but, should ONLY be used on rear position... as hard compound has reduced grip, which is not ideal for front tyre use.Please select non HC versions for front use.Product Video: https://youtu.be/o6X5PPct0Qc