"I bought this as a four part package (8879, 8884, 88000 and 88002) to motorise set 10254 The Winter Holiday Train which, in my opinion, is an excellent set and will join my Winter/Christmas diorama next Christmas. Initially I bought two parts just to make the train go but it went around the small track so quickly it always fell off! There are diagrams within the conversion instructions in the 10254 booklet but no details about how to use any of the apparatus so a ten minute job took me three times that to get it all going. However once set up the controls work beautifully. It's not a cheap option as nine batteries are needed in total and the four parts add up to over £40. I have used the parts left over to make a truck for the station and added a few extra minifigs to make the set look a little more realistic. (The "Challenging" review relates to my difficulty in understanding how the item worked in the first place!)"