The BD-R50 is a 50 GB Blu-ray disc by TDK. The TDK BD-R50 has a transfer rate of 72 MB/s. With the implementation of a layer of Durabis 2 the TDK BD-R50 is one of the most reliable Blu-ray media available. The BD-R50 is a Write-once disc and data written once on to the BD-R50 cannot be removed. This is the only major difference between the TDK BD-R50 and TDK BD-RE50 (which is a Rewritable disc).