Quality Park?. Redi Seal Envelope, #10, 4 1/8 x 9 1/2, Double Window, White, 500/. Redi Strip Security Tinted Envelope, #10, 4 1/8 x 9 1/2, White, 30. Quality Park™ Clasp Envelope, 7 x 10, 28lb, Brown Kraft, 100/Box.