Proform BB1901 Calibrated 3-in-1 Test Spring Kit

When accuracy is the difference between winning and losing, there's one test spring kit that's a cut above the rest...the RIMAC calibrated 3-in-1 test spring kit. This spring kit include three test springs: a lightweight spring, a medium weight, and a combined heavy weight spring giving you an approximate test range from 10 - 640 lbs. Data sheet included. Super accurate and individually tested on an Instron SF1240 testing machine.