The DG-6M5S model found in the Xbox One S is slightly different from the DG-6M1S found in the Xbox One, with the biggest upgrade being support for BD-UHD.
http://www.ebay.com/itm/Original-Blu-ray-Disc-Drive-Replacement-Lite-On-DG-6M5S-for-Xbox-One-S-Slim-/322353132838