10-pack of 100GB BD-RE XL discs, compatible with 4K. - Brand: SONY - Capacity: 100GB - Pack Count: 10 Pack - Type: BD-RE XL - Supported Resolution: 4K SONY stopped producing discs in February, and only stock remains. They're expensive on e-commerce sites. High-quality 4K compatible. Approximately 9 hours for BS digital broadcasts, and 12 hours for terrestrial digital broadcasts. That's assuming high quality, but I record detective dramas in LSR mode, fitting 26 episodes, a whole series. For the New Year's special, which is 2 hours long, I can fit 30 hours. I watch them on a 55-inch BRAVIA, and the picture quality doesn't bother me. If I don't watch them, I erase and reuse them, and these should last for 10 years. They work well with SONY recorders, and I've never had an error. SONY is focusing on entertainment, so I don't want them to stop producing TVs and recorders, but these are SONY's last 1000GB discs. Thank you for your consideration.