They're bolts for the wheels.
eBay has loads, from shiny to black.
Clicky this:
https://www.ebay.co.uk/sch/i.html?_f...er+75&_sacat=0
Security bolts are generally considered more trouble than they're worth. Many of the ones supplied with the car have been replaced by standrad bolts. Anyway, nobody wants to pinch 75/ZT wheels nowadays.
TC