small digital thermometer barely larger than a sugar cube !; already operating at the opening of the cardboard box; no on off switch; how long are they the 2 button batteries in use and how long will they still work ?; in any case it works (for a fridge or a bath) but it is very similar to the disposable; I'll try to get me a spare batteries; I would have preferred a switch, otherwise you have to remove the batteries if you do not use it; I'll let you know by changing this assessment of subsequent events (battery life, restart facility if we remove those, the device resistance over time etc.)
