they offered different thicknesses .I think acousticon 516 meant 5/16 thick,716 meant 7/16.that kind of thing,and I believe at one piont they were offering a few different bearing edges also,because of the technology they developed for the percussion stuff.They haven't really pushed the kits very much lately,but alot of people have really liked the snare drums,and the snares and kits are priced very attractively, a few years back MD did a comparison of pro line 6 piece kits and remo was by far the least expensive,out of at least 12 makers.I think the shells are a wood pulp and resin composite,I saw a how it's made or made in america segment and the shells are "spun"around a form,like a clockspring so theoretically they could make a shell at just about any depth or thickness.