Gilt bridges, 5 jewels
From thewatchforum.co.uk
"Ricoh also developed a range of unusual movements around 1976 - the cal510 is the best known, with two setting buttons as featured in my recent post on this forum. There was also a similar cal530 with a single setting button. And there was a cal(forgot the number - perhaps 520??) with the two setting buttons on the back - this movement seems to have been used in watches with two movements and two analogue faces together in a single watch head."
Button B (lower button) advances the time forward by one minute. Button A (upper button) sets the movement going after adjustment.
Battery 384