No more licking envelopes or stamps that can leave a bad taste in your mouth & not stick thoroughly. Universal Envelope Moistener eliminates the need to lick envelopes by gently wetting the desired material to activate the adhesive. Save time & effort required to do a mass mailing. Constructed with a long-lasting polyurethane sponge that distributes moisture evenly without over-wetting. Use with water. Squeeze Bottle MoistenerTransparent blue plastic bottle easily seals envelopes. Moistener Size: 2 oz; Color(s): Blue; Material(s): Plastic / Foam (Water-Fillable).