The SX4 Scenic Projection Changer with DMX Loop Tray with Shutters for Source Four from GAM is a system that offers a choice of four trays that snap into an ETC Source Four ellipsoidal allowing it to project patterns. This version employs a Loop Tray to add DMX remote control from a console to the SX4's impressive list of features. Like the non-DMX version, the DMX Loop allows the projector to display continuous moving effects such as clouds, rain, snow, fire, water ripples, and waterfalls. There are more than 35 off-the-shelf designs that will allow you to create a special FX/loop in the Loop Tray. With a required, separately-purchased DMX power supply and using a DMX signal, you can control the start, stop, speed, and direction of the effects loop. For basic use, you can simply plug it into mains power and set your speed and direction; no light control board is required. This version of the DMX Loop Tray has four shutter blades to allow masking off portions of the projected image.A PSU-51 power supply is required for use.