Mead #10 Envelopes, Security, Press-it Seal-it, 4-1/8" X 9-1/2", White, 45 Per Box (75026) Mead Press-It Seal-It #10 security envelopes; 45 envelopes per box White envelopes with self-adhesive seal; security lining for privacy Size: 4-1/8" x 9-1/2"