Works well with Simano brakes. Screw this into the reservoir cover and then push fluid through the caliper bleed port using a syringe and tubing (not included). Takes maybe 10 mins, works the first time, does a pretty good job of minimizing mess, and it can be done without a second person although it'd be easier with help. I've tried bleeding brakes tops down without this thing and it's hit or miss. Definitely worth the price.