LOT OF 4 Coherent AVIA LASER Nd:Yvo4 VANADATE CRYSTAL MOUNT

Description

LOT OF 4 Coherent AVIA LASER VANADATE CRYSTAL MOUNTS REV AD and AB
I don't know much about these they were part of an auction lot.  Here's what I can tell.
The larger one is engraved : 1125818 REV AD ,
On the sealed bag it reads : RMA 916209230
The 3 smaller ones at engraved with:  REV AB