Hydraulic brake levers move a piston in a fluid reservoir. On newer ones, they are mounted with the brake levers on the handlebars. Initially MAFAC made cantilever brakes, brake levers, and tool kits. It continued to be right-hand drive with external gearshift and brake levers. In the first drum brakes, levers and rods or cables operated the shoes mechanically. Trams were traditionally operated with separate levers for applying power and brakes. STI is characterized by its combined brake and shift levers, or "brifters". Simple machines such as pulleys and levers are widely used. Details like hand levers and the twistgrip use needle and ball bearings. Early prototypes had separate gear levers and clutch systems for each engine. Subtle but noticeable differences in hammers, loading levers, and cylinders help identify each model. This would disengage the autothrottle, with engine power then governed directly by the thrust levers. Other conventional levers and buttons are retained. This gun was cocked with external cocking levers on the side of the breech. There are many designs, including levers, screws, and ratchets.