The Sigma BC 1606L DTS comes in two versions. One with the cadence sensor and one with the cadence sensor as an option. Same computer just one comes with the cadence sensor and one does not. I have the one with cadence and it is wireless. I have had it about a month and it has worked flawlessly. I really like it especially the back light. I ride a lot at night and it is nice to be able to see the computer when I need to. You can even run the speed sensor on the seat stay so you can use it on a trainer and it will work just fine.