What I purchased is called the wizbangplus & they have a web site. They also sale them on e-bay a little cheaper than their own site. I paid $25/ea. Qlty of workmanship and components are top notch. G10 pcb and most of the components surface mount and power handling components, through hole. The design like most of the commercial units are from a design placed in public domain in 2000.
If you want to learn more about sulfation and these desulfators, do a search there is a lot of info available.
While boosting voltage periodically can help, I think the consensus is the high freq pulse designs is more effective.
The voltage boost approach is what one find on converters like PD with the Charge Wizard. I have one mounted in the MH. MH is connected to shore power for more than 90% of the time and the addition to the pulse desulfator had shown major improvements.