2 x Tape reel retainers for REVOX/STUDER A77, B7, A700, B67, A810, PR99, A807
So that they are non-magnetic. They will fit REVOX/Studer-style and other makes which use 'half-height' tri-spigotted reel motor platforms and will retain reels and NAB adaptors on 1/4" tape machines.