The adjustable ring base for your threadable lampwork ring topper with a
4mm high metric threading 2.5mm. Inclusive 2 rubber o-rings.
Fits for sizes from 16 to 20mm:
– US/Canada size 6 to 10
– British size K to U1/2
– French size 10 to 23
– German size 52 to 63
Made of brass, covered with a thick layer of pure silver (5-6 micron).
Compatible with all existing rings and components with 2.5mm metric threading.