Even by the standards of the seventies this watch was bulky.
Nicknamed “helmet”, I wore one of these for a brief period in the seventies and I did have a couple of adverse comments about it. I clearly remember a friend saying “I’m used to seeing all sorts of weird stuff on your wrist but that piece of scrap metal takes the cake.”
Despite its chunkiness, it won favour with the bloke who wanted to impress his mates at the pub. It came with two dials, white and black as shown here. Both dials are pleasant to the eye with good contrast. Apart from the colour, these two models, I believe the only two variations of the “helmet” case, are identical. Both feature a tachometer ring. Despite its extremely heavy case, the shape fits nicely on the average, or slightly larger than average, male wrist. It is now well sought after by collectors.
I don’t know when this model was introduced, the white dial version is a 1976 example and the black dial 1977 and probably one of the last; styles did start to slim down at about this time.
The movement is the legendary Seiko 6139B.