The source of the following data is the
German Osram website. In many parts of the world Osram is known under the name Silvana. Both bulbs are comparable OEM quality.
Osram H7 (product code 64210L)
B3 at test voltage 13,2 V : 450 h
Tc at test voltage 13,2 V : 930 h
Osram H4 (product code 64193L)
B3 at test voltage 13,2 V : 1100 h
Tc at test voltage 13,2 V : 2400 h
B3 = the time when 3 % of test bulbs had failed
Tc = the time when 63.2 % of the test bulbs had failed