I got it working for just a short time as I was taking pictures. Then it died on me. I think there is a short in the electronics that are fed by the single battery. The two batteries that drive the LED display hold their charge OK. Maybe there is a whiz out there that knows what the trouble is. As it stands right now the watch does not work. Band is sized for my 7 wrist. This worked fine since about 1979 then pooped out a couple of years ago. That is when I first noticed the big drain on the single battery. Batteries not included (uses 3 SR44). The keyboard appears black in the photos but it is a dark brown color. The item “HP-01 Gold Calculator Watch Model 1 Hewlett Packard HP-1 for Parts or Repair” is in sale since Tuesday, December 17, 2019. This item is in the category “Consumer Electronics\Vintage Electronics\Vintage Calculators”. The seller is “stealth4430rlg” and is located in Brookline, Missouri. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, South africa, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, New Zealand, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Barbados, Bolivia, Egypt, Luxembourg, Nicaragua, Oman, Paraguay, Reunion, Uruguay, Russian federation.