ANYONE EVER HEAR OF THESE VALVES

anyone ever hear of these valves DANZ INDUSTRIES 1/2 INCH MODEL # SVDF-15-12-D-12 i was supposed to get a set of 1/2 inch blitzluft valves that i did a buy it now off of e-bay but instead a month later thses show up def not what i ordered and i already have 4 blitzluft wanted another 4 to match. just wondering the quality of these are they comparable.