New digital tester is ideal for checking valve seat pressure on an assembled engine. Precision 1.0 lb/kg increments can detect a fatigued, broken or misaligned spring. Easy method to maintain a valve train. Can be used on most wedge engines with rocker shafts and aluminum rockers. Battery operated (9V). Four position adjustment and peak hold for hard to read areas. Capacity range : 0-500 lb/250 kg