Seemed to only reduce our mpg by 1-2 mpg for our Ford Explorer. One had a magnet inside that would just suck the buds out of your fingers. Considering other colors When I got mine at $250 a few years ago it was a mind-blowing deal. I will be returning these and keep my search going. I ordered the V3 version as pictured which I like better due to the shorter old version. Back it goes. In the case that you do wear it all the time. Der Schuh ist leicht, bequem und auch an warmen Tagen noch einsatzfähig. Other than that it charges fast and seems to have a good coil in it.