These metallic silver bubble lined bags measuring 180 x 250mm internally and 200 x 255mm externally will set your mailer apart from the rest. Our metallic bubble envelopes are made from laminated aluminium meaning they are puncture and water resistant and have a peel and seal adhesive strip for a tamper-proof, secure closure to keep your items safe in transit. These metallic silver bubble envelopes are a cost-effective solution for increasing response rates for direct mail and have 100 bags per box.