VELCRO ® Heavy Duty Stick-on Strips, when extra strength is needed this provides just that. Incorporating a 50% stronger closure and adhesive that can be used indoors and out, securing items such as large pictures, torches, rugs and tools etc. To use, clean and dry both surfaces. Peel backing paper and press firmly to surfaces. Allow 15 minutes to set (or longer for heavier items) before attaching hook and loop. Adhesive reaches maximum strength after 24 hours.