Check the listing for details. 2 different.Bellingham & Stanley Spectrometer adjusting scales sleeves c1950.. Condition: Used. Listed at 25.50 USD. This is 2 extra parts of a spectrometer by Bellingham & Stanley Ltd,LONDON.I cannot remember the name or number of it,but it was quite a big heavy instrument.They are 2 rings/sleeves 71mm dia outside and 67 mm inside with a height of 39mm.One edge has a locating slot in,and a very fine spiral ring with numbers marked around it to show the adjustment made to the length of the instrument in very fine steps. They date from the 1950s and is in what looks like unused condition,i have had them for about 20+ years and never used it when i had the full machine set up.I sold the spectrometer about 3 years ago.This part is made from solid brass and metal.I will post abroad but at your risk only with the ebay GSP post.It will be well packed in a box by me but i have had problems with parcels going abroad. Post in UK will be tracked and insured which makes it quite dear.Price and post is for both rings.