LED curtain jig

It's very hard to achieve exact gap between these [tiny and cheap neopixels] 1 without some kind of helping device. So I decided to make for my own purposes jig for soldering those tiny LED pixels. But after it was done, I thought that today I need gap between them with just this size, but maybe in the future I liked another numbers. So customizable jig was born. Maybe it helps somebody else too...