Holland Electronics specialty 4-way splitter is especially designed for HPNA environments (environments using existing coax cables and phone wires). It allows HPNA communication signals to pass through the splitters. It's a great way to connect your HPNA network, DSL, and voice communications on the SAME phone line simultaneously. Plus, the GHPNA Series splitters provide good return loss and isolation for in band frequencies other than HPNA.