Draper petrol engine compression tester 0 300psi0 21bar draper 37442 suitable for use on most petrol engined vehicles including motorcycles comprises 300mm flexible hose with 14mm and 18mm threaded adaptors large easy to read scale 0 300psi0 21bar and air release valve to allow rapid retesting display packed sold loose draper 37442 petrol engine compression tester 0 300psi0 21bar