PID Temperature Control Retrofit KIT for Rancilio Silvia [KIT-RSRTDNb] - $149.50 : Auber Instruments, Inc., Temperature control solutions for home and industry
PID Control Kit for Rancilio Silvia Espresso Machine | eBay
Rancilio Silvia PID Espresso Machine with PID - the Secret to Perfect Espresso Shots - YouTube
Rancilio Silvia + Auber PID - not controlling anything?
The Adventures of Cameron Charles: Rancilio Silvia PID Conversion