For Boy Scouts of all ages. Or perhaps James Bond fans.
Plated cufflinks. One end of the dome unscrews, revealing small screwdriver heads. These fit into the hole at one end of the cufflink (magnetic).
Dimensions (LxWxH): 25mm x 10mm x 10mm (approx.)
Weight per cufflink: approx. 10.44g (heavy)
Size = x mm (W x H)