Cactus is the first registered trademark of Harvest One. Harvest One specializes in designing and manufacturing camera and flash accessories. They are based in Hong Kong with manufacturing arms in China and Taiwan. Their philosophy is based on quality and innovation at an affordable price. Their design emphasis is on the wireless dslr market. The Cactus version 4 (v4) wireless flash system is the latest release. This is a 16 channel manual, i.e. non ttl, system. The power source is AAA batteries, and the wireless reach is about 30 meters. A compatible dslr needs to trigger off the center pin of the hot shoe. One needs to check a compatibility list first. Sony/Minolta users need an adapter. The receiver can be mounted directly to a flash stand or a tripod.
These units are serious value, especially where you don’t have a Canon or Nikon camera.
Pay a visit to http://www.cactus-image.com/