A trace-detecting computer input device such as a touch input device, optical tracing module, or optical tracing plate includes a trace-detecting module and a microswitch. The chair performs the function of a wheelchair while avoiding the appearance of a traditional wheelchair thus avoiding the invalid stigma often associated with wheelchairs. The male portion is inserted into a female receptacle and guides in the female receptacle limit the insertion of the male portion to a single direction. The first slave data server can be connected through a public firewall to the public Internet. The compositions of the invention provide stable visual indication, rapid initial kill, consistent long term kill with chemical and rheological stability.