Fairly straight forward, these are offered in the lengths shown.
7/16" bolts fit many factory seat belt locations, including European and Asian automobiles.
These Eye bolts are designed to work perfectly with the B15 Snap On Brackets. Offered in lengths and thread pitches shown.
Whenever a bolt or eye-bolt is used to attach a harness to your vehicle, you should use these wavy washers. One on each side of the sheet metal. They will help keep the bolt from backing out. These are not needed when using the machined sleeve/washer setup for pivoting bolt-in brackets.
We do also recommend using some form of thread locker.