You can get a threaded bracket that fits around the exhaust pipes.I bought one for my 996 and got the bracketss in the packet.I think they are available separately. I may still have one or two kicking around in the garage.
Ive got this one,its used but in good condition, a couple of small chips on the front edge,with the clamps for standard pipes.Came from Rip so its good quality carbon.£20 if its any use to you.
Sorry,Desmo had it.The clamps were for 45mm system.The Termis I fitted had the brackets welded on the pipe,this type of guard is no good as the hole centres are different.I used a standard 998 aluminium guard,the carbon one was no longer available.