[the_third_wave]

Yes, coaster brake hubs - "terugtraprem" in Dutch - are standard on the more traditional bikes. Those tend to run on 28"x1½" (40-635) tyres. The most common size is 28x1⅝x1⅜ (37-622).

As to arc lights that quote is somewhat - but not entirely - tongue in cheek. There is a metal-halide lamp in most video projectors (except for the more modern LED-equipped versions) and they're there for a reason, this being their wide colour spectrum. They do have quite a few disadvantages though ranging from their often relatively short life (in projector applications around 1500 hours) through the potential for self-destruction - older lamps run at higher currents and temperatures which eventually can lead to explosions - to the copious amount of heat they produce and the long startup time. Do you have a reef aquarium or do you use them as grow lights?

[eimrine]

Thank you for the answer with numbers, as another lifetime rider I consider wheels as the most important part of the bicycle and Youtube bloggers I have seen do not tell much information about wheel sizes.

I use MHL at kitchen because it makes food to look delicious and also at my workshop because sometimes I do some paint work. But a friend of mine uses MHL on growing phase and Sodium lamps while flowering because a proper use of LED requires a lens and sometimes even an active cooling.