Champion tapers are short so they can be used as a tapered reducer/increaser or as a cap type reducer/increaser.  The 26 gauge minimum thickness allows them to be used to vent fossil fuel appliances as well as in conditioned air distribution systems.  Tapers are normally stocked non-crimped.  Either end can be crimped by the installer or special ordered from Champion. Champion makes a full line of caps.  The new "universal" cap can be used to make cap-type reducers as well as clean out applications.  The unique lock between the top and sides is very durable and air tight.  All caps 4"-8" are made with this lock.  All other sizes can be purchased with either the clean out cap configuration or the reducer cap configuration.  Both of these traditional locks have been used in the HVAC industry for decades.  Caps are used to make reducers, plug round cut outs, cap off round pipe runs, and "tee" clean outs.