My new 45 purchased 2 weeks ago had the high green button and a mates 2 months old had the newer low button.I rang minelab today,service didn't know anything about which buttons they are coming out with.For those that don't know, the buttons some times leave the machines.Mine is one of that type.Ml. said they changed supplier but have returned to the original supplier and if mine falls to pieces they will replace it.If i'm in outback WA when it happens i will not be pleased. Rwork