Designed to switch on, an on-board relay when u whistle. Whistle again, and it switches off. Relay is rated at 5Amps, 220Vac. The whistle frequency can be adjusted, by means of a preset pot.
EFK 12001 Infra -Red Link
EFK 12002 Infra -Red Remote Control
EFK 12004 Telephone Line Recording Switch
EFK 12005 Sound-Activated Switch
EFK 12006 Touch Activated Switch