7 1/4 x 12" Jiffy Tuffgard Extreme Bubble Lined Poly Mailers. Mailers offer twice the protection of regular poly mailers. Self-Sealing. 5/16" bubble lined. Lighter weight and more economical than cartons. Use to ship electronics like phones and jewelry..Self-Sealing..Use to ship electronics like phones and jewelry..5/16" bubble lined..Lighter weight and more economical than cartons..Mailers offer twice the protection of regular poly mailers.