I purchased the GTM-60 because it is supposed to give more detailed and up to date traffic information than the power supply cable that originally came with my DriveSmart 60 LMT.
It certainly works receiving traffic information but I'm not sure at all it's any better than the cable which came free with my device. It's also supposed to receive weather information but except for one time in the month I've used it, the weather page on my Garmin has been blank
One suggestion if you buy this, do not pay any attention to the instructions which say you have to register the GTM-60 on the Garmin website for it to start working. The web page it listed had no place to register it, I called Garmin and waited on hold for over 30 minutes to be told, "Oh, I don't know why they still have that 'register thing' in the instructions. You don't have to do that, it'll just work fine without it." She was right, so just toss the instruction leaflet in the waste basket and simply plug it into your unit.