The temperature of the element heats to 1200C and the stainless steel cover gets very hot, so it must be laid on an inert surface (eg. concrete) when not being held.
It's very simple to use - first have all the bottles standing upright on a table/bench or floor or in moveable bins, put capsules over all of them, then plug the capsuler into an electric socket, wait (about 5 minutes) until the heating-element glows red and then (holding the wood handle) place the capsuler-head over each capsule in turn. You can see the shrinking through the hole in the top of the head. An electric extension cable is necessary if you're capsuling large numbers of bottles.