E-port conversion kit by ozroll - this kit enables you to upgrade from the old white ods battery handset too the new e-port battery handset both handsets work the same but the old handset needs battery replacements which can be expensive this conversion kit takes little effort too change your wall plate over to accommodate for the new e-port handset, with this conversion kit comes one wall plate only if you have multiple windows to change over then you need to buy one conversion kit per window and you will need to buy one e-port handset which will work for up to three windows.