It's a Walco. Not a high end unit by any means but it was affordable and works well as far as I can tell.
From their web site;
"Box Scrappers
The box scraper features two cutting edges for both pushing and pulling. Adjustable scarifier shanks loosen the surface to ensure an even and consistent finished surface. The cutting edges are made of high carbon steel and the scarifiers are forged and heat treated.
Standard Duty Box Scaper
4' Standard Duty 342 lbs"