I've used the ED-SunVis LEDS on a strobe circuit I built and they are bright even in day light. I plan on installing these same lights on a L-39 jet that I'm finishing. I build my own flasher circuits including the alternating landing lights you see on some full scale planes. I have not used they're landing lights though. For those I use the flashlight replacement leds that you find in Lowes and are bright in daylight. Send me your email and I'll email you a pic of the landing light that I installed in my Cessna 310.