We were able to use Thunder at safe revolution speed and could quickly drop the wall varnish of the house cypress. I think that it is very convenient and good product. However, I think that explanation is insufficient explanation to amateurs.
It is good to be able to finely adjust the ability (temperature) of the electric heater to 0 to 100. Also, it is good that noises do not occur like [Speed controller] using thyristors. However, since it is a variable transformer (weight is heavy) I think that it is not suitable for work (usage) that moves frequently (there is no need for improvement)
Sometimes it is a recommended product from Toshiba which was manufacturing slidac, and I bought Yamashita Electric machinery. Although it is enough capacity for use, it is solid and has a sense of security.