Selling these in sets of 100 envelopes for each lot. The box in the picture is just showing what they came in but they will be separated and sent in an envelope since I do not have a full box. Backs are self adhesive and secure. Please ask any questions Pack of 100 PACKING LIST ENCLOSED Envelopes – 4.5 x 5.5 Inches ULINE S-207 Pressure sensitive, backing attach securely to almost anything. Ticker 2.5 Mil poly for extra protection Listed size is the outside measurements. Side loading. Inside useable dimensions 4 x 5”