A package of 11 (10+1) 100GB BD-RE XL discs, compatible with 4K. - Capacity: 100GB - Quantity: 11 discs (10+1) - Type: BD-RE XL - 4K Compatibility: Yes - Product Version: Ver.3.0 These are high-performance Blu-ray discs from the renowned Japanese company, SONY. With 1100GB of storage, they are rewritable, so with this many, you should be set for 10 years. If you record a one-hour drama series per disc in LSR mode, you can fit 26 episodes. I also enjoy putting my favorite detective series on them and watching them in my free time. You can also store over 6 hours of high-quality video shot with a 4K camera. It's great for storing videos of weddings, sports days, and school presentations via a Blu-ray recorder. In my experience, HDDs tend to break down after about 8 years. Therefore, I back up important videos in case of failure. These are high-performance, last-of-their-kind SONY discs. Thank you for viewing.