The 100psi (7 bar) working pressure ensures adequate air pressure and flow to all the sources of the compression loss plus the percentage loss to be measured. 100psi (7 Bar) working pressure shows the source of compression loss as well as the percentage loss via the dual gauges.3 x 25mm long adaptors: M10, M12, M14. 2 x 238mm long adaptors for deep seated plugs: M12, M14. Adaptor hose (300psi) for diesel injection adaptors (as supplied in Laser Part No. 4510) 470mm long and adaptor hose for spark plug testing on petrol engines 670mm long.