I have one fitted on my Trek. Essentially it is a standard rack with slightly wider spacing between the stays and combined spacers to allow fixing to the screw holes on the drop outs. It has been rock solid for about 18 months, including a number of heavily laden trips with loaded panniers. Unfortunately I cannot make out the name of it, even with a magnifying glass, so sorry I am not much help to you other than to assure you they are available.
Edit: Just seen it is a Blackburn!