18" Clip In Volumiser Hair Extension by Christie Brinkley is designed for the woman with thin hair who wants the ease and versatility of wearing hair extensions but is concerned that her thin hair won't properly camouflage the individual extension pieces. This cleverly constructed volumising hair extension adds height, volume, and instant length. The base dimensions are 8.25" wide x 6" high and is made out of heat friendly synthetic fiber that can be styled with heat tools. The 18" Clip In Volumiser is part of the Christie Brinkley Hair2Wear Collection.