Super easy to use. Works with an easy, gentle process using mechanical advantage instead of brute force. Wear gloves and safety glasses. Just place a bottle cap into the capping bell and a magnet will hold in place. Brace the bottle so that it does not tip over and put the capper over it and with even downward pressure, pull down the handles down to the horizontal position. Voila! It has the satisfying finish clunk when it has closed the cap completely. You get resistance all the way and then it finally gives way with noticeable feedback and you know the bottle is sealed.
Yes, the majority of the capper is plastic, but it is not flimsy plastic like a toy, it is more like something you would make office chairs or auto parts out of. The device is actually fairly heavy and feels solid. There are many complaints about this capper on the internet because there is a CHEAP CHINESE COPY being sold on Amazon. You can tell you have one if the handles flex while you use it or the capping bell just fell off. Hobby Homebrew only sells the genuine made in Italy capper sourced from BSG and LDC. It will last you for years with no particular care other than some vegetable oil sprayed on the bell and other metal parts.
SAFETY NOTE: Do not use screw-top bottles. Breakage can occur leading to glass in your beer or other injury. Screw top bottles have very thin lips which can chip off as they are designed to be capped by machine, not by hand. Wear gloves and safety glasses. Do not use excessive force. Do not force the arms down past the 180 degree horizontal position it will break the capper. There are plenty of 90-second videos out there showing the right way to use it. It helps to lightly lubricate the inside of the capping bell with some food grade petroleum (See PetroGel) or vegetable oil.