Shimano altus m310 v brake 8sp shifter setrapidfire system uses ergonomic shaped lever for easy accurate gear selection featurespre installed fixing screw clamp ring 8 speed st m310optical gear displaycompatible with v brakes and mechanical disc brakesa 2 year warranty is offered with all shimano products from chain reaction cycles 3 years on dura ace and xtr products buyshimano componentsfrom chain reaction cycles the worlds largest online bike store