Is it brake pads? If so, most places wont advertise brake pads for smaller manufacturers, only for the larger ones. However, brake pads on a 50cc tend to be much-of-a-muchness. Take your set to a motorbike shop and I am sure they will have a pair in that will fit your bike
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix motorcycles.