So my first impression was not good as other users had some issues. So I bought a bottle as I wanted something to charge. First time fail (but I found a leak). Second time fail (but its still leaking). Third time and my bottle is charged to over 4,000psi and no issues. Reading every thing I can about this unit it's gonna eat o-rings and I'm gonna invest in some expensive lube but for a compressor that plugs into 117V outlet it does what it claims it will do. Just my first impressions. I hope this helps. Free from filling from others is worth something.