Bontrager Bontrager SpeedTrap Digital Speed Sensor
Bontrager's SpeedTrap Digital Speed Sensor conveniently plugs into any Bontrager fork with SpeedTrap technology for the ultimate in convenience. And, it wirelessly transmits speed data to your ANT+ cycling computer.
Features and Information
Compatible with Bontrager's Node computers and many other ANT+ devices.
I'm frankly shocked at Trek/Bontrager - they promote the integrated Speedtrap sensor when selling their bikes and then sell you a sensor (Part No 403683) that doesn't include a magnet which according to the Trek website costs the same as the sensor with a magnet (Part No 426619). There is no hint on the box that you are buying a sensor without a magnet, the only way to find this out is extensive research on their website. What you won't find on their website or in the box or anywhere else is an owners manual or any other hint as to how to install the Speedtrap sensor.
Bottom LineNo, I would not recommend this to a friend