A great set of filing trays! In Out and Pending maybe! 
Vintage Mid Century with a fabulous cantilever mechanism, which either opens them up to access each tray or closes them when not in use, for neatness and space saving. 
Dated 19th Feb 1962, it gives us a pretty accurate idea of when they were made. 
Measurements: 
27 x 35.5 x 14cm high closed/26cm open.