That means in a trillion braking attempts, it fails three times on average. It’s not perfect, mathematically speaking, but for practical purposes it’s pretty close.
The brake isn’t the usual handlebar brake lever customary on most bikes, and because it is wireless it naturally dispenses with the usual brake cable snaking down the frame of the bicycle to the front or rear wheel. To brake with the wireless system, the rider simply squeezes the rubber grip on the handlebar, which is fitted with pressure sensors. The harder the rider grips, the more pressure is applied to the front wheel brake. The signal sender is about the size of a cigarette pack and fixed to the handlebar. The receiver sits at the end of the bicycles fork and turns wireless radio signals from the grip into mechanical pressure on the front wheel.
Source: popsci.comAdded: 14 October 2011