The Innova 3612 compression tester has a large easy-to-read 2 1/2 dial face with dual-calibrated and color-coded scales. Packaged as a 4-piece kit for optimum use options. Product Features:15 high pressure rubber hose with 14mm and 18mm adaptersSide-release valve allows repeated tests without disconnecting the hoseHeavy-duty bourdon tube meter movementQuick disconnect fitting for easy removal and installationSeparate 12mm & 14mm adapters are also included for broader applications such as motorcycles, ATV, snowmobiles & watercraftAdapters feature high quality brass construction