The barrels bottom section were threaded by the previous owner for use in a Uni Hex. While this does not effect performance in anyway it does take away some of the collectability of these eyepieces. For those of you interested in actually using them they will work fine.
The barrel diameter is aproximately 1mm shy of 1 1/4 inch. You can make an adapter like the one pictured with very little effort. I included it with the 20mm when it sold last week. I have been using the bottom half of the barrel to one the many 25mm plossls that I have collected with my scope purchases to good effect since then .These eyepieces are great performers. Last Sunday on a night of terrible seeing they made an instant believer of a friend of mine who has just about every Radian and Nagler eyepeice that Al makes. They gave the best view of every eyepiece we tried. Bad seeing is bad seeing and nothing can change that but the Clave's were clearly outperforming every thing else on Jupiter. 175.00
each US shipping included.