Golden Number 50 Cufflinks

We have puzzled about these cufflinks among the staff at Benjamin Cufflinks.Golden 50thand Silver 25th - we understand that. But why did the manufacturer stop there? What about a Bronze number 8? Tin number 10? Wood number 5? Paper number 1 would be impractical, as would the wool number 7 - but they could get inventive!

Dimensions (LxWxH): 14mm x 9mm x 3mm (approx.)

Weight per cufflink: approx. 3.5g (light)