A. An integral PEX stiffener is not usually needed when using SharkBite since they come equipped with an integrated Tube Support Liner that effectively supports the PEX tubing to ensure the O-ring seals correctly. However, please be sure to check local codes as they might have different requirements. Additionally, note that the Tube Support Liner is not required when using SharkBite products with CPVC and copper, and can easily be removed if preferred or required by local code.