From the manufacturer:
Made of a natural, non-marking, rubber compound wrapped around an
anodized lightweight aluminum stem for outstanding durability and
consistency on every skating surface. The distinct tear-drop shape gives
more flex, bounce, and control while the signature dimples offer more
bite when starting and stopping. Available in Mint, Blood Red, and
Electric Yellow.
From Cruz Customers:
So far, feedback from skaters who've tried these stops has been good. They note these stops have good bounce, decent grab, and if you've had problems with wheels bumping or cutting into toe stops you've tried in the past, these might be a good choice for you. They taper up the stem so there's less material to get in the way of your wheels if you're a skater that likes to wear your stops up real high.
Sold as a pair.