Elektronika was the joint trade mark for the series of electronic devices such as computers, digitrons, VCR, tape recorders, digital watches, etc. All those devices were produced in the companies which were operated under the Ministry of science. Digital watches were first launched at the end of 1970's and their parts were produced in four companies - Angstrem (Zelenograd), Integral (Minsk), Sojuz (Novosibirsk) and Pulsar (Moscow). Five types of digital watches were produced in the entire period of production. First were led watches which only showe time by pressing on the button) the last ones were almost indetical to japan watches such as Casio, Citizen with typical functions (stop watch, alarms, dual time, etc.).
I only have two types since digital watches were never my focus.