Your search for "handlebar clip-on" revealed the following:
MOTOCORSE Machined from solid Clutch oil reservoir for Brembo radial racing pump - SPORT Colore
$319.00This product is created for peaople want to mount on the motorbike the Brembo radial racing clutch pump but don't...
Morsetto manubrio BMW R 1200 GS
$206.62The clamp is interchangeable with the original.CNC machined from billet aluminum alloy (Ergal).The kit also includes four M8x30 titanium grade...