4 1/4 x 6 1/2 - 24lb Western Sulphite SFI Dual Purpose Mailer - [White Sulphite, (SFI CERTIFIED), Vellum Finish, Spot Remoistening Seal on Large Flap, Two Side Seams Under, No Window, Remoistening Seal Below Perforation, Flap Extended] - 4000 per carton