One sensor for all pedals - On Trigger Extension kit
http://on-trigger.com
If you decide to buy a new pedal in the future, you don´t need to buy new sensors, just buy an extension kit for your new pedal. But if you've got for example two double pedals and you want to use a sensor on both of them, then buy yourself two sets of triggers. Frequent transfer from one pedal to another is not appropriate.
Video is for illustration only. www.on-trigger.com