Alright you GE experts, fill me in on this one.  Age?  I'm guessing it's probably 1980s or 90s vintage.  Not familiar with Trimline.  I know of the old Bonusline ballasts..

teach me.

Yup, it still works.  Yup, it has a black circular cap on the end.

How about that?  GE made a trimline stereo record player...   

https://www.youtube.com/watch?v=diBA38wir3I

Found this doing a search:
https://www.lighting-gallery.net/gallery/displayimage.php?album=229&pos=60046&pid=72012

Manufactured in September 1994. ‘Trimline’ was GE’s original name for their F32T8 series, used from 1987 until around 1997 when the ‘Starcoat’ technology was adopted.

Nice to see an SPX one of these too. Usually these are just SP.

thanks.  what does Spx mean?

@RyanF40T12 - Deluxe Specification Series. Just GE’s brand name for triphosphor. SP for halophosphate/triphosphor blend and SPX for pure triphosphor.

Trimline lamps were GE’s copy of the earlier Sylvania Octron family of tubes.  So and argon-filled range designed for operation on 265mA ballasts.