Kaoko on a Breva 1100--I love it. I've had various throttle locks on various bikes and it's about my favorite. If your bike can take an NEP throttle lock, those are very good too, and cheap (Guzzi content).
I also recommend the NEP lock. I modified the most appropriate version to fit the Griso, and it worked very well, taking up almost no space. (But I removed it after installing a Rostra electronic cruise control, which is my favorite modification of all.)
Moto