Buying a Thor laser from ebay.... question about model number

[MapsAndLegends]

I just got an ebay gift coupon and want to use it to buy a Thor M2 blue laser from ebay. I haven't messed with laser pointers in a while and I feel like grabbing a new one. Especially since I've misplaced my existing bright blue pointer.

I'm seeing several listings with model numbers like BZ6-A, QB2-B, BZ6-C. BZ6-MC. Also some are just labeled MII and some are labeld MII-2.

Does anyone know what this means, or where I would look to figure it out? Does it matter?