size: This vent bag are designed to fit 4 inch diameter dryer vent pipe, 4 inch diameter vent elbow and 4 inch dryer vent hood.Design updated: Made of polyester. The opening of the bags is with loop strips which will help you quickly put these vent bags on or off the vent rain cover.Convenient to use: No other items such as string, clamp, magnets, wire or screw will be needed if you use our vent cover bags. The hook and loop fasteners would do the job.Application: Eliminate the problem of birds' nests or dryer lint dust. The lint bags can not only catch the lint but also allow proper venting.size: about 39 x 25cmMaterial: Polyestercolour: blackPackage Contents: 6 x dryer lint trapOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.