#333 is a dual function Laser Photo & ContactTachometer. Photo RPM measurements are taken via the laser photo method, same as model 332. Contact functions, including various rotation, distance and frequency measurements are made with the acessory heads. Zippered case, three contact adapters, reflective tape, instructions & 9V battery included. 12 Different Measurement Modes High intensity laser beam not affected by shop light, detects RPM from up to 6 feet away Memory function saves up to 10 min/max/avg date records Great tool for easy and accurate measurement of RPM Reflective tape and 3 contact accessories included.