pete asked me to comment on some of the responses............better than a window regulator that does the same thing??........lets see.......replacing a regulator takes someone with experience several hours to do both doors if you consider that you also have to re-adjust the windows to eliminate wind noise and water leaks and remove and replace the upper and lower door panels and when you are done the improvement is marginal.........how can you compare that effort to plugging 2 wires into existing slots in the fuse box, removing the underdash cover, putting it back in place and attaching a ground wire to just about any screw where you can get a ground connection............this would take almost anyone at least 15 minutes..........and when you are done your windows will move almost twice as fast as they previously did...........if your windows were already somewhat fast they will now be superfast...........if they were painstakingly slow they will still be twice as fast as they were before...........in this demo i chose the car on my lot that had the slowest windows...........if yours are faster to begin with they will be even faster--------now about a 2 dollar relay...........i may not be the best engineer in the world but i am a darn good one for sure...........a survey of the US patent office will show that i have nearly 40 patents half of which are electrical/electronic related and i can assure you that in my wildest imagination i cannot figure out how i could ever duplicate what this box does even with a 2 thousand dollar relay.........even so if this box does what i say it can do what difference would it make if all it had was a 2 cent jelly bean inside???...........this is a great product that is long overdue to solve an age old problem with the cars we all love so much............i first built one of these over 20 years ago to help the windows in a Ferrari that had windows even slower than what is in our gn's............it was so slow that i used to grab it with my hand and help pull it up...........twenty years ago it cost me nearly 300 dollars to build and it was big as a brick............for several years i have wanted to revive this product but never had the time............modern surface mount components allow this unit to be one fifth the size of the original and cheaper to build......... those that know me personally know i have an impeccable reputation for honesty and treating people right and i want to keep it that way............i promise you that this box is full of transistors, resistors, integrated circuits, capacitors, inductors, potentiometers, lots of solder and a quality thru hole plated circuit board......R Clark