Review on Wireless Remote Shutter Release: Vello FreeWave for Nikon DC-2 (D90, D3100, D5000, D5100, D7000) by Cool Martin

The range of these remote controls is extremely limited, especially when you're not looking at the receiver or the antenna isn't fully extended. If you lean a little to one side or the other and don't extend the antenna, it literally won't work beyond 5-10 feet. The LEDs are really very dark. The unreliability of the trigger is made worse by the fact that since you can't see the LEDs, it's very difficult to tell if you've actually triggered it. Also, the fact that foreign batteries are used in both the receiver and trigger makes it impractical. Changing the battery in the trigger is also a real headache: to change the battery you have to unscrew two very small screws and remove the entire back cover. Literally the worst remote shutter release I've ever used.