The product was delivered on time. The 1st start requires opening the circular housing cover to remove the cover that isolates the battery (supplied with the equipment) or the system is done with the plastic housing, at least the cover is so soft Phillips screwdriver that is quick to round the cover notches without managing to open the case ... when I could finally open the case (now with a battery compartment lid in poor condition) I removed the insulation and replaced the battery lid: Switch on ... nothing! Test the battery meter = 0 volt, battery flat, stale ... I hope that this is an exception and that all is not well supplied with flat batteries. I do not recommend this too lightweight anemometer.