Magnetic retarders are similar to the electric retarder discussed below. A simple retarder uses vanes attached to a transmission driveshaft between the clutch and roadwheels. Vehicle braking is provided by a retarder and two oil cooled disc brakes. Sugar water acts as a retarder for the curing of concrete. The hydraulic converter includes an integrated retarder (brake). When a fluid coupling is used for braking it is also known as a "retarder". This system provides electronic activation of all braking system components including retarder and engine brake. The addition of a retarder slows the evaporation rate of the water. This type of retarder is known as compression release engine brake or "Jake brake". The retarder slows down the engine when brakes are applied. This also works as part of the engine brake retarder in the exhaust system. An accelerator speeds up the cure reaction, while a retarder delays it. The transmission system uses a (5-speed) mechanical gearbox with clutch, torque converter, and retarder. Electronic stability control is also available along with a permanent magnet retarder. The chassis has various options like air conditioner, retarder, full air suspension, automated transmission.