Staco Energy Variable Transformer 3PN1020B

I have this Staco Energy Variable Transformer 3PN1020B. this item it appears to be new, I have a couple of them and a few of the smaller version. Please do your research on this item. I have a few of this items and a lot of Varian valves. https://www.ebay.com/itm/Staco-Energy-Variable-Transformer-3PN1020B/182836590665?hash=item2a91e8f849:g:OQEAAOSwrhhZ5bvG The last picture is the small type that uses regular household current. 562 552 four zero eight zero