PID Retrofit KIT for Rancilio Silvia w/ pre-infusion
[KIT-RSPb]

What a difference this makes to my espresso! Consistent temperature, fixed brew time, pre-infusion all combine for a brew that is much much better than nearly every coffee shop. Instructions were easy to follow. Everything worked the first time. Very, very highly recommended. I installed the blue LED version -- very nice looking, too!