Does anyone know the diameter of the bezel? It would be great if there was a diffuser for short distance, flood. If the dimension is non-standard, I may be able to make some and send a few out to those interested.
No, typically a group buy is a special low price for people who want to buy a new light early. Sometimes before it goes on sale to the general public. You do have to sign up to BLF to post on this forum and to join any BLF specific group buys. It can be any type or brand of flashlight or any product really. Could be a battery charger or flashlight accessory.
Sometimes BLF members will help with a product design or help with organizing the sale on this forum by answering questions or updating information on the sales. This reduces the workload on the company selling the light. It also gives the company a certain amount of sales right away. It can also help a company know if their product is desirable or not by how many people want to buy it.