Temporary, safe, and easy to use.

Temporary, sure. It's a hairband.
Safe, though? How unsafe can a hair accessory be?
And how easy, exactly?
As easy as tying a ponytail...

~ Your hair is secured into a ponytail with the elastic band.
~ The hairs may be arranged over, under, or to one side of your natural hair.
~ However you style your hairs, it should be comfortable to wear!

A word about safety...

~ Too much pulling can actually cause permanent hair loss, a condition known as traction alopecia. Hairs should not be secured in such a way that your natural hair is pulled too tight, too heavy in any one spot, or uncomfortable in any way!
~ When you no longer wish to wear your fake hairs, remove the ponytail slowly, as strands have a tendency to wrap around the elastic band.
~ Gently untangle stray strands with your fingers after each use.
~ The best method of storing fake hairs is hanging by the band, on a hook, coathanger, or nearby branch.
~ Hairs may also be rolled into a bundle, and stored in a pouch.
~ Hairs do not play well with closures such as zippers and velcro! Remember this.
~ The hairs may be washed as necessary with gentle soap and warm water.
~ Hang overnight to dry. Drying with heat is not recommended!
~ Acrylate fibers are very sensitive to heat, and respond to temperatures comparable to the heat of direct sunlight.
~ Direct sunlight, open flame, and other sources of heat may damage hairs.
~ But, this also means that hairs may be styled somewhat with tools set to extremely low heat.
~ Products containing alcohols may damage the acrylate fibers in the fake hairs. Read the ingredient list before applying any product to hairs. If you are not sure, test on a small portion first.
~ Brushes, combs, and other hair tools do not work exactly as intended with fake hairs. Comb yarn hairs gently with your fingers. Silky hairs may be gently combed or brushed, starting at the tips and working upwards toward the band. If you find a snarl, carefully work it out and try not to damage the hairs - fake hairs do not grow back.
~ Bearing in mind that fake hairs do not grow back, you may yet feel it is necessary to shorten your hairs. This is really quite an easy thing to do. Knot the hair tightly at the new length, and trim off the old end with sharp scissors.
~ That is all!