They are Far East manufactured Porsche 993 Turbo copies from a company called compbrake.
Max disc size is around 330mm and configured for a 34mm wide disc......
From way back when 16" rims were for supercars only and brakes needed to supplant diameter for width
They're as wide as my house......Lots of pad choice sometimes used by the T5 Volvo community as they bracket able for use under 16s
Same hydraulically as the 996T Caliper but troublesome to get to fit on a VAG