If you've got the good fortune to be riding a Dura Ace or Ultegra four arm crankset, but you missed out on the opportunity to get your cranks with a pre installed Pioneer Power Meter, then Power Meter Installation Kit for Consumer Supplied Cranks is your salvation. The kit consists of a magical box, and the process is simple. Just drop your Shimano crankset into the box, drop the box in the mail, and wait for some seven to ten business days. During that time period, the alchemists at Pioneer will be transubstantiating your crankset from a shapely alloy article to a power gathering data magnet. When the crankset returns to you, it will have a Pioneer power meter installed.