They feature inbuilt spacers and speedrings that prevent the shields from being crushed from overtightening. They are filled with Boa's industrial nano-ceramic grease used in the Blackbelly Ceramic Bearings. The nano-ceramic grease will help to polish the steel balls over time and keep them performing at their optimum. These are based on their years of experience making high-quality bearings, tested by thousands of riders worldwide.
They come packaged with a nice metal tin and foam insert to keep the bearings nice and secure.