Good news for all those who have welded roofs by hand up to now. The new UNIDRIVE 500 from Leister makes your life easier. Why? Because the small, 4.5 kilogram semi-automatic hot air welding machine combines manual and automatic welding in one handy device. Welding close to the edge, welding in small spaces, at least three times faster than manual welding, and so on. Doesn't exist, you think? Yes, there is, we say. If you read on, you will find out why.