The ASL 138 Extremity Control Joystick is a very small profile joystick designed to be used for clients with decreased range of motion in their extremities. It has a resistance of about 1/3 of a standard joystick. The optimal use for this joystick is mounted at the chin, because of the outer shell it is resistant to saliva and other foreign objects that get into most joysticks. A feature this joystick has is in changing the slide switch on the interface will allow the client to make the reverse direction be reset. This will be a benefit to chin joystick users so you do not have to find another switch site for reset. Along with the ASL 624 Swivel Joystick Mount, the small profile of this joystick allows it to be mounted in almost any orientation. The ASL 624 Swivel Joystick Mount is required with this joystick (not included).