PID kit for Rancilio Silvia Espresso, w/ Pre-infusion, White Display 701098739352 | eBay
PID Temperature Control Retrofit KIT for Rancilio Silvia [KIT-RSRTDNb] - $139.99 : Auber Instruments, Inc., Temperature control solutions for home and industry
I installed a PID on my Rancilio Silvia for about $50 : r/espresso