These are open face bolts.
This bolt is made from a nylon-like material that is lighter but stronger and more durable than delrin. It will not swell or shrink with temperature change. This bolt has a cupped face and great air flow. NO oil needed. This bolt comes with ball bearing and spring system. Choose with or without O Rings. Each bolt is hand made here in the USA.
The Bandit Bolts Griffen Bolt is older, so while it may be available used and in a few cases new, it is not commonly available anymore.