This is a stunning & rare chronograph from Nivada Grenchen . Size 38.5mm x 48 x 14mm including domed acrylic crystal.
I have only ever seen one of these before with this stunning gradient dial  in this classic sixties case with sharp tapered lugs & solid polished stainless steel case.
Really study this watch on the images as its a beauty.
With a grey pebble dash dial that goes from darker to light pale grey and many varient shades depending on the light.
With the gold radial chronograph registers & white tachymetre register round the outer dial with gold 5 minute indices .
It has a bi directional bezel with 1 to 12 markers in black etched into the bezel.
I have paired it on a lovely Rios  rich dark brown strap costing £30 that really compliments it so well.
Its in very good condition & the Valjoux 7733 manual wind calibre is running accurately over 24 hours.
I have to say its one of the best looking vintage chronograph watches I've come across. From a Brand whose Vintage Chronographs are really increasing in price.
I bet you wont find another of these out there let alone in this condition.
Find a link below to Vintage Nivada Grenchen.
https://www.fratellowatches.com/a-brief-history-of-time-nivada-grenchens-complete-brand-history/#gref