Sorry it’s in French / Grâce à moi c’est en français. The French version I found was higher quality. Here’s and English one:
The SEF fire selector stands for Sicher = Safe, Einzelfeuer = Semiautomatic, & Feuerstoss = Automatic.
And here’s an X-ray view:
Regarding Umarex. No wonder the guns are so damn cheap!!! BTW what is 22lr? I know airsoft and bb.
22lr is a common abbreviation for the .22 Long rifle cartridge. It’s a very small rimfire cartridge often used for hunting small game and recreational shooting (due it it’s low cost). For reference it has about a third of the energy at the muzzle as a 9mm Luger round does (the most common pistol cartridge).
Here it is (bottom left) next to other cartridges for scale.
Thanks for the write up!
Glad I was able to help someone learn something!