The Manufacturer, the price preferential benefit, the quality guaranteed, may different need to have custom-made the product acc LAN (pulse XFMR filter) and LAN-master (RJ-45 + XFMR/LED) Common mode chokes, VoIP XFMR, ISDN, T1, CEPT and XFMR ADSL line XFMR and VDSL XFMR/filter Micro filter splitter (CO/CPE side) POE (power over Ethernet) drivers 10/100 and 1000base-TX network filter modules T1/E1 ...