After watching several YouTube videos and reading the reviews, I'm convinced these jacks are all made by the same Chinese company. You can find them in price ranging from about $90 to about $130 for the 4 ton jack. I ordered one of the more expensive jacks because it was advertised (pictured) as being "yellow" instead of the majority color of orange; received an orange one. The warning labels on the.$90 model are identical to the $130 model. Does the jack work, absolutely yes. Although I haven't used it in an off-road necessitated situation, I did try it out at home. I tried it both with exhaust, and with air compressor. The jack will not work if you have dual exhaust, unless it is dual exhaust into a single outlet pipe with a diameter no greater than 3 inches. It also won't work properly if you have exhaust leaks anywhere in your exhaust system. Using compressed air the jack was filled to capacity using no more than 40 psi. The jack easily lifted my jeep wrangler from the side (both same side tires off the ground) and from the front (both front tires off the ground). Inflation time was about 3 minutes using both methods. The compressed air method was easier because you don't have to hold the hose on the exhaust, and with compressed air you can easily adjust the bag as needed during the initial inflation. Once deflated, the jack compactly stores in a convenient carry bag, which I stored under my rear seat. This jack is just one tool that can mean the difference between being "detained" (being able to get out by yourself), and being stuck (needing someone to pull you out).