A cutter including a base, a holder, a cutter blade portion, and a laser generator. An amalgam retainer is positioned in the arc chamber and is abutted against the constricted area. A wide range of signal parameters are measured on the dehopped signal to characterize the radio performance and the compliance to the radio specifications. The collar defines an opening therein. In the internal combustion engine, a stratum of air andor air flow is formed between a fuel spray injected from an injection valve and the top face of a piston andor the wall surface of a combustion chamber, and a face shape contrived to guide the air flow is formed on the top face of the piston. Certain features can improve product freshness both during shelf life and during consumer use.