This is by far one of the BEST tools I've bought this year! Once used it was very easy to replicate this process for other shock/strut projects. I found: 1. That the knurled lock ring needs to be tightened every other turn of the clamp screw. It "weakens" because the spring is flattened.2. The lower locking jaws could be a bit longer. Being short, initial setup was a little awkward as they wanted to slide. You can only tighten the knurled ring enough because the spring is inclined when at rest.3. The overhanging upper jaw may be a little longer. Because this jaw was short, the entire block tended to tilt to one side on initial installation. I noticed that the dirtier the spring, the less the jaw slipped. 4. The draw bolt body contains sufficient lubricating oil. I didn't have to oil it the first time I used it. I re-greased after the second project and this block continued to drip oil. Oil sparingly!5. I had to watch how-to videos from other manufacturers and managed to piece together how to use this device. With this in mind, many videos have said to be hand tightened with a socket wrench while others have used an air wrench to "tighten" and say how dangerous it is and that they shouldn't do it that way. I settled on a socket wrench, giving it a half turn until two detents were learned. That is, where the knurled locking ring no longer hangs out. Then I made 6 to 8 full turns, and the spring was compressed enough to form a 1/2 inch gap. After installing the new shock, I made 1 to 2 full turns to loosen and remove the compression tool. ALL 5 stars if not for my listed points. Overall I love this tool!