Product details:

These hydraulic COMP Cams mini valve spring testers are designed to be portable and low-cost alternatives to bench-top style spring testers. Each of these 0-1,000 lb. testers is scaled off in 20 lb. increments and includes a recalibration feature. Their hex-shaped body can be placed in a vise, used with an arbor press, with the addition of a flange (sold separately), or in a drill press.