Just to stretch you all a little more....

GE (and others) also make a similar Halogen Bulb, an H7604.

H7604
Candle Power 100,000
Watts 50
Beam 7 x 5 deg
LIfe 100 hrs

4509
Candle Power 110,000
Watts 100
Beam 12 x 6 deg
LIfe 25 hrs

Q4509
Candle Power 140,000
Watts 100
Beam 7 x 7 deg
LIfe 100 hrs

I have used some of the H7604's. The have a support inside the bulb
that is obvious that its not a 4509... They lasted fine but have a
narrower beam. Better for landing light, poor for taxi.

Mitch