There is a nylon loop at the top of the extension with a micro ring already attached. All you have to do is to put your natural hair through the loop and pull at the loop. It automatically pulls the hair through the micro ring. And then, all you need to do is just squeeze the ring with a pair of smooth-jaw pliers.
If you want to remove them, all you have to do is to open micro ring and remove it. It won't damage hair because it have no adhesives and chemicals are involved.
The hair origin is Chinese Remy which can last up to 2/3 months, its tangle-free and high-quality.
How many bundles do you need? On average, it should take around 4-5 bundles to create length/volume for a full-head. You have to take in account matching the density of your clients’ existing hair, so if their hair is thicker or they have shorter layers, you may require more bundles, but if their hair is fine you may be able to complete a full head with less bundles.