[Better material]:304 stainless steel thickened material Thicker and more rust-proof.Better quality than ordinary stainless steel. And the product has been black painted, which is beautiful and rust-proof. [Size selection]:Please note that product size 4 inches means it is suitable for 4-inch pipes or holes.Rather than the air outlet diameter of the product being 4 inches in size. [puunkeey Features]The dryer vent cover is designed a round flat cover with 45°Louver to prevent rainwater from flowing in; and built in fine mesh grille to stop sundries and small pet from entering . [Service details]: order to better protect the products and deliver them to you intact, we pack the products in cartons before shipping out. Thicker product, less likely to cut hands. for all tumble dryer vent pipes / hoses, bathroom vents & extractors, air conditioning units, kitchen fans & vents, all home wall vents, heat transfer and ventilation systems, gas & electric dryers, cooker hood extractors, as well as a wide variety of industrial uses. A replacement of the old or rust vent cap for your house. Colour:Black Material:304 stainless steel Size:10cm Package Contents: 6 x air outlet mask 12 x screws 12 x expansion tubes 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.