Guardian Ignition Interlock is CO’s most affordable ignition interlock device. Guardian’s device is discreet and one of the easiest to use devices on the market. With over 30 years of experience, Guardian is one of the most trusted iid brands. Our location at 2727 W 92Nd Ave Unit 40 is CO certified with expert technicians for all your interlock installation and calibration needs. Guardian alcohol monitoring products include 24/7 customer support so we're always here when you need.