First one delivered did not work so had to be returned at my cost.Cost me £7. Second one arrived and worked OK. The readout is not very big so is not easy to see but seems accurate. I am not blaming the supplier for this as i should have realised from the sizes this was going to be the case. The design of the gadget means that it catches on the flip up lid to the socket but does go in far enough to make contact. Have a KYKKA tpms in my other car and this was less a third of the price and works much better and shows temp without having to push a button, but not as neat. Although it arrived in 4days it took 3weeks to get a replacement as they said it could not be returned 11days as they were closed for christmas/new year. So ended up taking more than 3 weeks in total.