I have installed the lamp instead of Grothe 17V S1 (2 Watt) in my bell system. Although the nominal power is 3 watts slightly higher, this is nearly offset by the higher rated voltage again. The function is good and the lamp very inexpensive. However expensive was the shipping to 6.95, the delivery came in a middle carton, although the 3 lamps that I had ordered, would have fit in a suitably padded envelope. So a really inexpensive product was at the end but not so cheap.