So weird to actually be holding this in my hands. Which is funny since I own several 8cm CDs and DVDs (even an 8cm DVD-RAM) but something about how absolutely Not A Product this was is fascinating. These were on the market viably for like 3 or 4 years maybe. Flash media took over optical media for HD video so quickly it barely had time to become a real product line. Theoretically dual-layer 8cm BD-Rs and BD-RE DLs could have existed, but the whole 8cm blu-ray concept was dead so early on that I'm mostly sure those never made it to market.
Supposedly Verbatim and maybe a few other brands actually released 8cm BD-Rs and BD-REs in English markets (mostly the EU I believe), but besides some pictures on long-sold out e-commerce sites I can't find any real evidence those existed.
This Maxell BD-RE disc is the only 8cm BD-RE you can find for sale online right now as far as I can find, shipped from Japan for a pretty penny ($34.77 USD plus shipping on my end). The only other 8cm blu-ray listings I can find are for TDK single-write discs. Supposedly Maxell made single-write discs and TDK made rewritable discs, but I cannot find either of those anywhere. So yeah, this product line is just about dried up of old stock materials. I'm almost nervous to open it, which I'm not usually about this stuff :p