In about 1 year I have 5 pieces consumed and now I have to re-order new (well, that I have old order from Amazon yet found, because I did not have to search long).
However, I find the shelf rather moderate, the lamps are at about 1-2 hours a day and hold less than a year (5 pieces I have now used up in 11 months). If so again at the next delivery, I'll switch to no-name lamps. It seems not to be worth buying branded goods
