These needles are the correct size, and should not puncture the liners if appropriately applied WARNING: Item cannot be returned or exchanged if liner is broken or punctured due to poor inflation or needle use A flexible liner suitable for different head designs supplies comfort and security Detachable humidity-resistant liner https://finndkcab.snack-blog.com/30707762/5-tips-about-speedflex-adult-large-you-can-use-today