Complete your party decorations with our Balloonify Black Mylar Number 4 Balloon. With a number '4' design, this custom balloon can be paired with our other Balloonify number and letter balloons. Made of mylar, this party balloon is moistureproof. This metallic balloon's sturdy construction ensures durability and reusability. With its self-sealing valve, this mylar balloon stays inflated and in shape for a long time. This graduation balloon's simple inflatability allows you to fill it with air using a hand pump. This number balloon has an aluminum black finish, adding a transcendent look to your space. For easier assembly and decorating, this birthday balloon has an integrated hanging loops. Measuring 40 inches in length, this foil balloon can be inflated with air or helium. To reuse this balloon, gently deflate, properly store, and carefully reinflate without overfilling. Shipped deflated in a 1 count box. This party balloon can be easily inflated with the included straw, providing you with full control to help eliminate the risk of over-inflation. Electric air balloon pump (SKU: RWP1061) is available and sold separately.