This is a replacement for expensive clip-less pedal systems used on bicycles. The commercial versions require a special shoe/pedal combination. This item allows you to use any old shoe, and the existing pedal of your bike. Your bike does not have to be modified in anyway. Unfortunately one pair of old sneakers will have to become bike only shoes.This is an easy way to double your power output when on a bike. You will be able to apply force on your downward and upward stroke. I've notice a big difference while using them.I've biked 30 miles using this system so far this season. No wear and tear detected. I'll update this later when I've put more miles on.Print out two of the plates, one for each shoe / pedal. I used 1 extra shell and 30 percent infill. Lightly sand the connection point, and ensure you can slide the male end through the receiver easily. Glue the male end onto the bottom of your shoes, I used plain over the counter krazy glue and it is holding really wellBolt the female end to your pedalThe goal is to have the balls of your feet inline with the center of the pedal.You can "snap in" to lock your foot in place by aligning the male female ends and applying pressure. You will get use to where your foot has to be, some practice is required.To release your foot apply upward pressure and slide your foot away from the bike.If you have never used a clip-less pedal system make sure to practice first, if you come to a stop and panic its easy to fall over before you remember to free your feet.