This is fantastic, it holds a charge forever, my sister tried mine and liked it so well, she bought one for her car and is planning to buy additional units for the other cars. I also bought one for my grandson's car and intend to buy for my daughters later. I highly recommend this product, the clarity is excellent on both ends, I have even used it in the house for hands free talking. The only problem has been if I forget to turn it off, if I am to close to the vehicle, it answers it and I wonder why I can't make a connection on my phone...I did this at the UPS store and had to run out to my car to get the unit. When other people saw it, they wanted to know where to purchase one, so I told them...hey do you think I should get a commission.