Looking for an incredibly durable HIGH QUALITY non-o'ring chain? Look no further...these will definately outlast the sprockets! Formally known as the HTK (Hamburg Trading Company) Panther. Fastech-Racing tested this chain using a PRD Fireball TAG package and racked up OVER 50+ hours and two full rebuilds on ONE chain, believe it or not! PLEASE NOTE: A wider chain tool required, i.e. Coleman, KWH, Righetti or CC.