On old pipe setups like Coffmans, West Coast, Jetsports, Butches, ect... You would cut a ring or two off of the tail cone to shift the powerband to higher RPMs. Pipes are desgined to provide more power in certain RPM ranges. Shortening a pipe's tail cone was a way of changing where the pipe's powerband is. Coffman and West Coast I know of had short and long tail cones for Kawasaki 650's. That is what the seller means by the tail cone not being cut.
Short = top end
long = bottom end
Factopry Pipe products came out with their tunable head pipe that is used on the ever popular "B Pipe" people use for rec riding and freestyle on their SJ's. The FPP head pipe has three screws that you can adjust to control the amopunt of water added to the exhaust streams of gases. Sonic waves travel at different speeds based on the temperature. So by adding more water you cool the pipe and exhaust gases down more which in turn slows down the sonic return wave giving you more low end. Same effect as having a long tail cone.
Hope that helps. Also google how a two stroke pipe works, it is all about sound waves.
