The tiller, with forward/reverse directions and speed controls, is the steering column central at the front of the scooter. The tiller may contain other features also, for example, a speed limiter, lighting controls (for nighttime use) and turn signals. A battery use indicator is also often included. Forward/reverse direction can be controlled by thumb paddles, finger controls, or a switch. There are two types of mobility scooters: front-wheel drive (FD) or rear-wheel drive (RD). The front-wheel drive is usually a smaller device and is best used indoors. Rider weight capacity is a minimum of generally upwards to maximum. The rear-wheel drive is used both indoors and outdoors with rider weight capacity of . A heavy duty rear-drive can carry up to , varying by manufacturer.