A brake handle for a bicycle can look different and have different types of function to brake your bike. The most common is a hydraulic brake handle. But there are also wire brake levers. In order for the brake lever to fit as well as possible against your caliper or rim brakes, it is always best to find a brake lever that is adapted for your particular caliper or rim brake. Also keep in mind that there are different lengths of the brake arm itself that you affect when braking. There are also different handles depending on whether you use DOT fluid or mineral oil in your brakes. There are also different brake handles if you want to be able to integrate your gear levers into the same bracket. Do you suspect that your brake lever is leaking oil? Change it right away.