Polyx breaker technology with their polyx breaker continental bring pkw know how to the bike tyre arena polyester has been used successfully for years in car tyres and been tried and tested many times the extremely resistant polyester fibre is woven tightly crosswire making a very high fabric density which not only makes the breaker more resistant to foreign objects but is also resistant to punctures the rolling resistance is not effected either by the polyx breaker blackchili compound