This is a one of a kind drive unit. I built this back in 1984 for use with my Celestron 11 telescope. I have since computer controlled this telescope and no longer use the drive unit. The drive electronics are built around the Bradford West Quartz telescope drive board. Four BCD switches with digital readout give you over 10,000 drive rates selections. There is a plug installed on the back panel which supports a 12 volt Dec. motor. The unit has two clock boards installed, one for Sidereal Time, the other for Universal Time. Each clock has three buttons on the back of the drive unit that are used to set the hours, minutes and seconds of each clock. The unit also has a built in timer on the hand paddle for timing your photo or ccd exposures. The timer is reset by either a switch on the top of the hand paddle or by a reset button on the hand paddle. The unit has been wired for use with an ST4 autoguider unit. The drive, clocks, timer and autoguider all function perfectly. I am asking $350.00 plus shipping and insurance for this unit. The displays on this drive are bright, but have been washed out by the camera flash unit. Thats for looking!