Comes complete with all instructions and theory of operation. All you need is a soldering iron and wire cutters. The displays plug into a socket for easy removal. 12 hour and 24 hours settings. Great for Ham hobbiests, etc.
Digits are large enough to read across a room.
They make great gifts. Comes with plug-in transformer for total protection. With a jumper wire can be built to work on 50Hz for foreign countries.