Business Source Heavy-duty Clasp Envelopes - Clasp - #93 - 9 1/2" Width x 12 1/2" Length - 28 lb - Clasp - Kraft - 100 / Box - Kraft - Heavy-duty clasp envelopes feature an open-end style, reinforced clasps, and deep gumming on flaps for a secure seal. Metal clasp with rounded edges is plated for rust-resistance. Large flap and superior gumming secure documents inside. 28 lb.