I bought this for my Garmin streetpilot i3. Upon connection it made the unit bleep continuously and the display showed lots of different graphics. It went bananas! The reason is on the original it has a choke in the lead, which I assume keeps the current constant, this does not. I would return it but the delivery costs are more than the lead. I have now bought a garmin lead for £18 from a leading motorist retailer and the unit works fine. Forget this.