Hello Toni, The "Raid" was very similar to the "Racer" as you have probably noticed. However they have a slightly longer "Height" - or caliper arm "reach".
Measurements from central mounting bolt to center of brake pads:
Racer: 48.5 - 63 mm (small) Racer: 53.5 - 68 mm (large) RAID: 65 - 80 mm
Raid also has greater "Width" between pivot bolts:
Racer: 62 mm Raid: 75 mm
So, the Raid would be used for frames and forks which have greater distance between fork blades and between rear stays. Good choice for wider wheel rims and wider tires, and for frames built with more space allowed for mudguards (fenders).
I have only seen these used on one bike. That was an early 1970s Rene Herse Touring Tandem, which had 650-B wheels and wide alloy fenders.
Bob Hanson, Albuquerque, New Mexico, USA