I saw some in Turkey. They are really just a light bulb socket with a electical cord to plug into the wall mounted to a metal tripod. The tripod legs space the bulb by fitting tight against the open end of the drum after it is placed inside the drum. I would not really buy something like this, especially imported. A few more trips to the hardware store could yield a workable DIY version. The lightbulbs are just normal houselight bulbs. It is not a complicated contraption. It just works really well for the task. They just let it heat up as much as necessary and turn it off. Or on larger size drums leave it on the whole time. Depends how much space is between the head and the light.

Piece of cake, even I made one. Light socket, electrical cord, plug, on/off switch to put on the cord where you can reach it, coat hanger. Use a coated coat hanger, bend the ends in, rig the light socket et al so that it fits where the hanger would normally attached to the clothes rack. Even a 5 watt bulb puts out a lot of heat so start there. Try to keep a good distance between the head and bulb.

don't use a normal switch, use a reostat(?) so you can adjust the temperature via wattage - if you want it deluxe - keeps it where you like it.