Just finished this baby a few minutes ago. Bronze liner super zippy has the Rapier II motor in it. Has 3 strokes built in, 2.5mm fineline 1-5 tightsNew Bulldog Rotary 001.jpg, 3.2mm standard 5-7 round liner, and 4.2mm long stroke for large liners 8-14 round liner. It has just the right amount of weight 5.5 ounces well balanced. Comes with 3 give springs from light to hard. These are $350 and take me a couple days to build. I also have steel and aluminum frames as well.