While the Heated bed thermistor included on the back of silicone heaters are generally inaccurate, taping one somewhere else isn’t exactly a better option, either. So why not do it right once and for all?
Ebay:
[US/UK/CA/AU] http://goo.gl/jbX1sG
[DE] http://goo.gl/Yn4bCv
Amazon:
[US] http://amzn.to/1P18UYb