These needles are the right duration, and will not puncture the liners if thoroughly applied WARNING: Product or service can't be returned or exchanged if liner is weakened or punctured because of incorrect inflation or needle use A flexible liner designed for different head styles provides convenience and security Detachable https://adult-medium-speedflex75532.imblogs.net/80496428/the-best-side-of-speedflex-adult-large