This is a dyno thst uses a disc brake from Chevy S10 truck as the absorber. The brake assembly is free to turn a few degrees. When a load is applied using screw device on master cylinder, the brake assembly rotates and torque arm of known length pushes down on hydraulic cylinder of a known area and gives a reading on pressure gauge. Using simple math or my spreadsheet this pressure id used to calculate torque. RPM is obtained from digital tach. Knowing torque and RPM the HP may be calculated. It also can be used for engine break in. It comes with two 212 predator non hemis for parts and a 212 hemi thst is complete. Also comes with ARC flywheel and rod for non hemi. $500 OBO Lou Nixon 904-540-3676 call or text