Our HeliumFree™ 18" Balloons are the World's Strongest Balloon! Specially engineered plastic polymers with metallic flake keep them looking shiny, brilliant, and fade-free for months to years! These are the only internally-seamless, air-filled, permanent and reusable balloons on the market today. Whether you are in an arctic, tropical or extremely windy region, no balloon can stand up to the elements better than DuraBalloon®. We recommend replacing DuraBalloons® every 6 Months or so due to inevitable dirt and grime build-up that may reduce their original bright shimmer. DuraBalloon® heavy duty balloons are round in shape and easily screw into their Fiberglass Stem Holders. Inflate via the FastFlow Inflator/Deflator, our Hand/Foot Pump, our Inflator Tip with your bike pump, or any other compressor / automotive service center with a tapered inflation nozzle.