Odd Unusual Orphan Metric Collet

Description

This is a single orphaned aluminum collet that I'm unable to identify. The bore is 12MM, taper is 30 degrees, the groove is 1/8" wide, major diameter is 25MM and it's about 16-1/2MM tall. It's very high quality, obviously professionally made and appears unused. It may be rare enough that someone is desperately looking for it.
Please scrutinize the photos and don't hesitate to ask for more if there's anything else you'd like to see. A local buyer is welcome to pick it up at my home in Southeast Massachusetts to save the shipping time and cost. Of course I'm happy to combine shipping so do check my other listings just in case. I leave feedback as soon as I notice an item's paid for; my buyers are always satisfied with my items and service so I don't need to wait to see the feedback they leave me first. Thanks for looking!