I have looked for a long while to consider the merits or demerits of this type of jack and finally put my hand in my pocket. I found it well packed, it arrived quickly and in good condition. You have to fit the valve and connector bracket + plus hose on the base plate but that is two screws only and takes just a few minutes. I found that I had to cut the hose a bit to prevent a kink after fitting but that's better than being too short.The jack is sturdy and quite robust, the quality seems good too, time will tell on durability of course.I chose this one as the footprint is compact at circa 12.75"/324mm square and the bracket sticks out about 3.5" / 88mm or so. I changed the air fitting for a PCL type to suit my garage installation but that was my requirement or choice and not an issue with the jack at all. It works very well, it is fast and stable at all heights and meets every claim made within the advertising and videos that are available if you search the Net. The biggest benefit for me is that with 99% of modern cars, particularly those with under engine covers is that access or availability of hard points for safe jacking are fewer and fewer. It is pretty usual to jack the car on the suspension and be left with not enough room for an axle stand, however because of it's small footprint this is better for placing under the sill jacking point which leaves you room under the suspension for the axle stand. Now you could argue that a trolley jack will also go under the sill which is true but the air bag takes up less room and is a darned site quicker too. You can get these that have different handles some are long with remote operation of the valves etc and with wheels and are more like a trolley jack in use, it will just depend on your needs. It is great value for money, well made and functions as described, if you are thinking of an air jack this could be your choice. I do need to state that I am a working from a well equipped home workshop, so regular use but not
The Tech Reviewer 
