Perforated Aluminum Wall & Ceiling Repair Patch is a self-adhesive fiberglass mesh over aluminum for tough repairs without rust. The perforated aluminum patch allows compound to penetrate and create a strong bond. Ideal for ceiling repairs where extra strength is needed to hold the compound and prevent sagging.• 4" x 4"• Color: White• Easy to use• Repairs and reinforces interior walls and ceilings without a complete tear-out• Compatible with plaster, drywall and stucco• 20 % thinner letting you create a smooth paintable finish with less effort• Expanded aluminum patch allows compound to penetrate for a strong bond that doesn''t rust• 15 % more fiberglass provides strength for a repair that resists cracking.