Ultra Hold is Acrylic based clear non-yellowing formula .This adhesive have the leading standard in soft bonding. Ultra hold is the ideal product for extended wearing of hair system bonding holds 3-6 weeks. Ultra hold is thicker use only single and thin layer. Allow dry before placing the unit on head. Ultra Hold Liquid Hairpiece Adhesive 3.4oz .2-6 weeks hold, depends from person to person and the climatic conditions.