I just found a picture of that percussion massager. It wasn’t a Sunbeam, it’s a Conair. The Conair Professional. The great thing about it is that the heads are very close together and have an elongated shape that makes a nice pocket with each head resting nicely on each side of the shaft. Most of the other models from other companies have the heads spaced too wide. Unless you’re built like John Holmes, the heads don’t even touch. I like the infinitely adjustable speed slider too, so you can get the speed just right.
Over the years the twist on replaceable heads got worn out inside and got loose, so I just glued them on permanent with 2 part epoxy. I’ve had it I bet 10 years now. I have to buy another one just in case they stop making them.