You've been asking for these - they look a lot like clamshell covers - they are for connecting to the ends of ball chain. Squeeze shut over the end ball, add a tiny drop of glue for extra security if you like. Fits 1.2, 1.8 and 2.4 mm ball / bead chain. 3.7mm x 7.3mm x 3.3mm By the pack of 5.