There are ten different types of 8400-Series voice terminals: the 8403, 8405B, 8405B Plus, 8405D, and 8405D Plus, 8410B and 8410D, 8411B and 8411D, and 8434DX. The 8400-Series voice terminals work in both 4-wire and 2-wire DCP configurations. The following applies to 8400-Series voice terminals installed in a DEFINITY G3V3 (or later) system. The 8400-Series voice terminals have programmable voice and touch-tone transmission parameters that must be set to the correct values in order for the terminals to operate within the required limits of the installation.