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 25cm Material: Polyester colour: black Package Contents: 6 x dryer lint trap Only 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.