ECM Flow Control is a nice and easy way to get pre-infusion if your espresso machine is not plumbed in (ie. you are using an internal reservoir). I purchased an ECM Synchronika from idrinkcoffee, and at that time, idrinkcoffee was out of stock of the flow control kit. A few weeks later, the ECM flow control was in stock and I purchased it. I installed the kit myself. Installation is very easy if you want to do it yourself. The spring that comes with the flow control kit is used to replace the spring that goes below the group head (not the spring above the group head). This replacement spring is more robust. When re-assembling parts, be careful not to over tighten anything. Firm, but not too tight. Use electrical tape or some other form of coverage to protect the mushroom head and the other part below the group head from getting scratched from your wrench. Maximum flow (at about 9 bar) should be about 6ml/sec without a porta filter (about 60ml or 60 grams if using a scale when the pump runs for 10 seconds). I tried pre-infusion for between 10 and 20 seconds, followed by a 25 to 30 second shot time (or even longer -- experiment and have fun!). I'm not an expert espresso sipper, but I did notice a difference in flavour with pre-infusion (using the same Datara Farms coffee beans). Profiling is an "art" and is not for everyone. However, the pre-infusion is great if that's all you want to use the flow control for. I pulled shots with 10 second pre-infusion, followed by full 9 bar pressure and then declining pressure to about 2 bar for total time of 50 to 55 seconds with great results. The only nit I have about the ECM flow control is that, depending on the grind setting, I had to turn the knob of the flow control about one and one-half full turns to get full pressure. Not a big deal, as the knob is easy to turn around fully. Note that the flow control may feel a little stiff to turn at first, but after several uses, the feel of the turn becomes more smooth. Enjoy your espresso passion with this wonderful upgrade! If you have any questions, the staff at idrinkcoffee are nice to deal with. If you are within a reasonable drive of the idrinkcoffee store, its worth a visit to their awesome showroom to try out the flow control (it was on display on a Synchronika).