Mitas ET-01 Trial tires Suitable for front and rear tires of trial motorcycles. The ET-01 2.75-21 is suitable for use on roads, either in poor condition or in good condition. The tire is designed for use in trial and enduro competitions where classic off-road tires for enduro and motocross are not allowed. ET-01 is original equipment from the GasGasTrial Contact ES with electric start and trial school.