Late '70's/early '80's Pacer 2000 computer. Not mine, although I'm the kind of person who would hold on to something like this.
Description from an old post:
" You set the wheel diameter by opening the back and entering the binary number for the diameter by moving 8 tiny micro switches with a pencil tip. It used the flat Polaroid batteries. I had trouble with wet weather. It registered in hundredths of a mile."
