The devices and methods taught in this disclosure are directed to facilitate the observation, collection, transportation, storage, and preservation of specimens possibly containing DNA, said specimens potentially constituting evidence of sexual assault. The first lead includes a contact element, an extension element extending substantially in the direction of the die pad, and a concave surface disposed between the contact element and the extension element. The use of an infrared filter suppresses stray IR radiation resulting from plate phosphorescence. This result simulates the torque slip characteristics produced by transfer case having both a center differential mechanism and a viscous clutch. The permanent magnets have a generally rectangular shape and are preferably arc magnets or breadloaf magnets. The open centerbody is centrally disposed within the twisted mixer and helps to provide efficient cooling of exhaust air from gas turbine engines.