The following beads are generally for use with external renders or areas where there is high moisture / humidity or where applying a polymer modified or sand / cement finish. The mesh wings provide an excellent mortar key and the solid edges create true straight arrises, corners and finishes to render runs. Fixing is generally by mortar dabs or stainless steel nails or staples. Galvanised fixings should not be used to avoid bi-metallic reactions which cause rust spots.