It is basically a Multi rig, but with an extended hair to put multiple bottom baits on rather than a standard bottom bait.
I use it a bit on Nazeing and had some good fish on it, usually with around 3 8mm wooden balls on the hair, or at times a 20mm bottom ball, a 15mm pop-up and a meshed bait.
http://anglinglines.com/blog/how-to-the-kebab-rig/