This high quality plastic slide mailer is made from polypropylene with a flip-top, snap-on lid.It holds up to 5 standard sized (25 x 75 mm or 1"x 3") microscope slides. There are inner slots to keep slides separate.The snap close lid can prevent slide breakage and block dust from contaminating microscope slides.The plastic slide mailer can also be used as a staining container, with a minimal amount of solution being used.10 slide mailers / pk