ive had mine for 3 years & its great. it starts beeping & flashing from stuff as far as 8ft away, it has 3 light (green thru red) & 3 beeping stages, yes the light turns red with a solid beep tone when ur 3 ft from something, but any one with decent driving skills should be able to judge another foot or so, i mean how close do u want to be, u cant be butt up against another car when parallel parking, gotta leave room for a car behind u to get out. when backing out of a driveway it sounds off if a kid or bike comes into path, for that alone its worth it! plus its a strong step that allows u to reach up top. plugs right in, comes with a lock, & can be taken out in a minute & used in another vec, if need be. bought mine off ebay for under 110, they cost alot more now. theres also a different brand of sonar step but i forgot the name.