Old and rare Clavé barlow (negative achromat f/113.4mm).
There are scratches and wear on the barrel but no dents dings or serious damage. The lens has some fine scratches and the coatings are mostly gone but images are still bright and clear. Barrel size is 27mm, extension diameter is 29mm and adapter is 53mm/29mm and was used on Clavé focusers.
This is a nice collectible for a Clavé lover, not a substitute for an Astro Physics Barcon ... heh.
Best offer received by close of Memorial day gets it, but please figure in $5 to your offer to cover CONUS shipping cost.