To be honest I would buy this product again, the only issue I have with it is the Adaptor design. Unfortunately the fit between the fixed fitting on the hose and the adaptor it鈥檚 not tight enough, you can only tighten it down by hand and that O-ring doesn't keep it tight. Sadly I didn鈥檛 have the brain power to see if the fixed fitting fit the head of my vehicle before putting the adaptor on, I put on the smallest adaptor, which is the same size as the fixed one on the hose? . Midway through my compression test I got to a cylinder that had a corroded spark plug hole, and I didn鈥檛 realize that until I screwed in the adaptor with the hose, after removing the hose I kept on doing the compression test not realizing that the corrosion grabbed a hold of the adaptor and got it stuck in the head, I didn鈥檛 realize that the adaptor was stuck in the head, because the fixed fitting was the exact same size on the hose, and then continued to finish my compression test with a weird hissing noise coming from the motor whenever I rolled it over. I then continued to put in spark plugs, and the dam thing threaded right in to the adapter, broke my expensive ass spark plug and then dropped the broken chunks of the spark plug into the cylinder bore.