What do you call a factory that makes really good products?

When the wheel was invented, it caused a...

I come in pairs but I’m not shoes, I sparkle and add color to you. I near your head, but you'll never hear a word said. What am I?

What five-letter word becomes shorter when you add two letters to it?

Used by climbers and lifters, even acrobats at height. Or snapped with a string that's pulled very tight. I can write in many colors, the most common is white.