※ This is a cushioned envelope with a thin air cushion on the inside, designed to accommodate the thickness restrictions of the mail service. It's sized to fit one smartphone or small item. ※ Internal dimensions: 140 x 210mm; External dimensions: 160 x 210 + 40mm (manufacturing tolerance: + -5mm) ※ Thickness: Approximately 4mm; Bubble height: Approximately 1.4mm; Weight per sheet: 10g ※ Country of origin: China; Materials: Polyethylene, Kraft paper (92g/m2); Color: Kraft color (brown); With sealing tape; With opening tape ※ Applications: For storing small items. Compatible with Yu-Packet and Click Post. ※ Not compatible with Nekopos and Kuroneko DM-bin.