Hi the rep crazy hours movement is a modified 21J movement which makes it jump on the hour , all rep movements are above for this crazy hours, don't get fooled with some sites saying ETA etc is my advice the dial is not a straight forward swop due to the feet positions are diffrent on the gen and the reps, when I started I paid a local watch guy I'm in contact with in the UK to do all mine but over time he teached me in steps so now I can do it myself and set the time etc, this time last year I would of screamed on doing this task but now I feel I can do it, mind you I doubt I be doing any unless I'm asked or I do it for various fellow friends, I'm quite impulsive so I nearly have or had all the colours already, i think that's why he teached me because I kept coming to him with more & more watches he!he!