Standard or Classic Hand controller
Here is the newest version from Losmandy

Use Hand Controller buttons to center the star in the eyepiece. Note: Press and hold a direction button on the hand controller to move the telescope. To move the telescope faster, momentarily press and release the opposite button while continuing to depress the original button.  The speeds will change from guide, to center, to move then slew with each push of the opposite button.   The Dec and RA reverse switches on the new version are on the bottom end, one on each side of the connector.

These can also be plugged into the ST-4 Guide port to test the guide inputs are use it for manual guiding.