If you have cable internet or are using the coax cable inside your house for MoCA networking, you might eventually want to split a cable outlet between 2 end point devices, e.g. a set top box and a modem, or a network CableCARD tuner and a MoCA adapter.
You’ll need a digital splitter for that, and the most important spec for the job is the frequency range the splitter is rated for. It must be from 5 to approximately 1000 MHz. I say approximately because some splitters that work are rated for 5-1002 MHz.
Splitters that have worked for me – most recently with an Actiontec ECB6200 – include the Extreme Broadband Engineering BDS102H, CommScope SV2G, and Regal ZDSB3DGH10. If you can’t find any of those or a splitter that meets the 5-1000 MHz spec, then get one from a cable company truck. I did this myself years ago by just hanging out in the cable company office lot until a truck came by. I told them what I needed a digital splitter for, and they tossed me a couple.