If you shoot weddings, events, industrial or other location work, Pro-Sync is for you. Pro-Sync provides cordless, remote flash control with virtual immunity to interference. Unlike radio frequency (RF) remote flash control systems, Pro-Sync uses state-of-the-art coded infrared technology to fire remote flash units. Common sources of radio interference, like cellular phones, pagers, and cordless microphones (increasingly common at weddings) can disrupt radio flash control signals, but not Pro-Sync. And because the Pro-Sync signal is encoded, it cannot be triggered by any flash or light source.The transmitter can be mounted on, and fired by any standard camera hot shoe (or connected to a PC terminal for off-shoe use). Just slide the compact transmitter onto your camera; no cords, no antenna, nothing to clip to your belt. A pair of "AA" batteries in the transmitter powers up to 5, 000 shots, with recycle times averaging less than a second - faster than most any flash- so your Pro-Sync is up and ready when you are.Each time you shoot, the transmitter fires, and an "explosion" of coded infrared light fills the room, bouncing off walls and around corners. You can't see the signal (neither can your film), but the Pro-Sync receiver can.Plugged into your remote flash, the Pro-Sync receiver is in a "standby" mode. Pro-Sync receivers are incredibly sensitive and can easily pick up the signal from behind backdrops, soft boxes, even around a roomful of wedding guests. Nothing else can trigger the receiver, not even a full-power flash fired inches away. They work indoors or out, with a maximum range of 600 feet (indoors).The receiver draws power from the flash to which it is connected; there are no batteries to change. Receivers are available with either integral "H"-prong (household-style) or monoplug (European-style) sync connectors, so they connect directly, cordlessly, to most professional flash units or power packs. For additional versatility, each receiver also has a standard PC terminal.PRODUCT FEATURES:Economical, basic infrared remote control system;One private-coded channel, compatible with additional Wein Pro-Sync receivers on "channel 1";Can be used with TTL camera flash by adding optional Synk Lynk accessory.