Speed sensors??

Hi, my girlfriend is interested in using Zwift. I’m after a cadence/speed sensor for her bike. I’m using the garmin version on mine. Is there any cheaper alternatives? 

 

Regards Oliver. 

Here’s a link to the Cateye sensor I got for my bike, assuming your GF has a “basic” setup.

http://www.amazon.com/gp/product/B00B2PT2L0?psc=1&redirect=true&ref_=oh_aui_detailpage_o07_s00 

I also recommend the low profile pedal magnet…

http://www.amazon.com/gp/product/B0085N7KDY?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00