This product has lighting proof function ADSL splitter/filter can eliminate the interference between data signal and voice signal transmitted in the same telephone line and make the internet and telephone go both at the same time(Data signal for internet voice signal for telephone) The structure of Adsl splitter/filter: One RJ11 at one end for line. Two RJ11 at the other end for phone and modem. Size of product(mm):59*44*23 Size of carton(mm):220*280*380 Qty's(PCS)/CTN:250 N.W(KG):0.036 G.W(KG):9.5.