I'm using an HKS turbo timer(left). the wire harness was separate. like 4DRMR2t said, I don't know that any one brand is better than the other. although I do wish mine had the cabin temp thing.My HKS has several features: speed, RPM, 0-60 time, 1/4 mile time,2 times for turbo cool down. don't know how acurate some of that stuff is. I just use it for the timer. I did try the 1/4 mile thing a couple of times-got 13.8, 13.6..I dunno? oh, the light is blue and flashes red when in timer is counting down