Replacement Bulb On Street Twin

Hello,

I think I need to replace the standard bulb. Either I am getting old, or the bulb isn't strong enough but on country roads at night, when a car comes the other way, I can't see a bloody thing in front of me until they pass. I know I have only one bulb not two, and new cars seem to have brighter lights, but jesus it is hairy at times.

It seems like this kind of thing is going to work:
https://www.autobulbsdirect.co.uk/h4-osram-night-breaker-laser-next-generation.html

On Amazon though, I noticed different packs for bikes and cars. Is that all just marketing?
https://www.amazon.co.uk/Osram-6419...qmt=p&keywords=osram+h4&qid=1573245183&sr=8-9


Oh, and what is the difference between single blister and double blister?