The HDBM48 is a 4K HDBT 4x4 Matrix Switcher with simultaneous optical & analog audio outputs, and HDCP2.2 Support! DON'T BOTHER BUYING ANY SWITCHER THAT DOESN'T SUPPORT HDCP 2.2. ALL FUTURE MEDIA REQUIRES HDCP 2.2...OTHERWISE, YOU'LL HAVE A BLANK SCREEN ON YOUR TVS. This switcher allows you to route 4 input sources (Bluray, Cable Boxes, Directv, etc) to 8 output sources (Televisions, Projectors, etc). It comes with the 4 necessary HDBT receivers so that you send can send your HDMI signals up to 230 feet away via CAT5 or CAT6 cable. The HDBT receivers don't need to be plugged in, it gets power from the matrix. It supports full 4K resolution and up to HDCP2.2! It comes BRAND NEW with remote control, power cable, rack ears, RS232 serial cable, and IR extender. The simultaneous optical & analog audio outputs are incredibly important and necessary! Let's say you have 4 Apple TVs going to 4 different Televisions. Additionally, you have multi-channel amplifiers powering ceiling speakers for each of the televisions. Apple TVs don't have optical outputs anymore...only HDMI outputs. So with this matrix, you would simply plug the Apple TV HDMI outputs into the 8 HDMI inputs. And then connect the simultaneous optical audio outputs to your multi-channel amplifier...quick and easy! This setup would be much more difficult with other HDMI matrix units with no optical audio outputs. You would need to buy a bunch of HDMI to optical audio adapters, as well as many more cables....it would be a mess! Also, no other HDMI matrix has as many convenient control methods as mine does. RS232 software and web browsing control is ready out of the box! The HDBM48 is guaranteed to perform just as well, or better, than any other matrix in the market. Even those that sell for $5,000 or more! Don't be fooled by the AV industry! There is no need to overpay for the latest technologies!