Sekonic RT-3PW PocketWizard Module for L-858DSekonic RT 3PW PocketWizard Module for L 858D Sekonic Transmitter Module RT 3PW for L 858D Speedmaster light meter. Used to trigger Pocket Wizard enabled receivers and lights. Features: Zones Groups: 3 Zones (A to C) for ControlTL, 4 Zones (A to D) for Standard mode Channels: 3 Channels for ControlTL, 32 Channels for Standard System Flash power control On Off Model Light Control MPN: SE RT 3PW