Source: Sensor: http://amzn.to/2BFwNom 4" blast gate: http://amzn.to/2CuSioO Other components: https://ivacswitch.com/ (buying from these links will help support this channel, so thank you!) The iVAC Pro System can automatically turn your dust collector on and off, and also open and close your blast gates automatically when you turn on your power tools. Information here: https://ivacswitch.com/ivac-pro-blast-gate/