What binoculars are these please?

[flintlock]

Hi Everyone
Has anybody got any idea what these binoculars are and what they were used for. They are about 10 inches long.
The two nurled knobs in the last picture when rotated bring a yellow filter over the lenses, further rotation brings a green one.
They were given to me some twenty years ago and I've never looked at them until now!
Any help would be gratefully received.
Thanks
John

[Richie B]

British Royal Navy. AP = Admiralty Pattern.

see here :-

GB 9 - Collecting Military Binoculars

[flintlock]

Thanks very much Richie much appreciated.
The binoculars in your link are definately like the ones I've got.
Thanks again.
John