Only 1 star because it isn't any good when used with a bus powered hard drive---one that gets its power from the USB cable. It may rate more stars for other slower or lower-powered devices or storage that has an external power supply.
The item received was a F3U134b10. The Amazon description says this is a 12Mbits/s cable i.e. USB1.1/full-speed rather than the faster high-speed standard that Belkin imply. The UK Belkin site has a technical bulletin that says 480Mbits/s i.e. USB2 high-speed and the cable says USB 2.0 compliant on it.
Although I didn't buy it for use with an external hard drive, I thought I would try it. It didn't work with the a bus powered hard drive---it wasn't even recognised by the operating system. I wouldn't seriously use a 3m extension for hard drive storage normally anyway.
It did seem to work for with a flash pen drive and a USB-1.1 12Mbit/s device, so you may find it is ok for scanners or other full-speed/12Mbit/s USB devices. However, I wouldn't recommend it for storage i.e. hard drives, or anything where you may regret loss of data.
For the price, if you only want 12Mbit/s it's good. If you are thinking of using it for a hard drive beware---you may lose your data. If you do use it for an external hard drive, only do so if the drive has an additional power source.