When installing, you are instructed to use small bundles of 1/4 inch in thickness laid flat.
For thin hair or just for smaller bonds you can use bundles even 1/2 this size. These tiny bundles wear just as long, or even longer, than larger bundles.
Larger bundles and larger bonds are NOT recommended for satisfaction, success and the safest hair extension wear. Keep those bundles small!
Thinner hair may require some extra concealing by back combing the hair right above the hair extension bond to create a thicker cover.