Lightweight and economical, these GoSecure bubble lined envelopes are designed to be impact resistant. With a bubble lined interior and an exterior made from 75gsm MG grade paper, these envelopes are ideal for protecting delicate or fragile items in transit. Featuring a sender address box and a secure peel and seal closure, these size 4 white envelopes measure 170 x 245mm (internal size) and come in a pack of 100. The bubble that inner lines the mailers is produced using a minimum of 30% recycled content.