The present design relates to the ornamental features of a drill chuck adapted to releasably attach to an air impact drill. A pilot operator is selectively moveable within the passageway, and a flow metering operator is moveably disposed within the passageway. The cutter unit includes a drive roller unit and a belt cutter. Precursor compounds to these novel mercury-binding compositions contain structural moieties that may be represented as:where X, Y are individual atoms or are functional groups consisting of several atoms, such that the atom bonding to sulfur is not hydrogen. The temporary clamping structure for electronics is arranged such that the fitting pawl is unfixed from the fitting hole by bending the tip end of second protrusion of the electronic device body in the direction in which the second protrusion goes away from the first protrusion.