A simple and longterm solution to an age-old problem that's easy to install! This high-quality brass permaseal provides a secure and permanent connection between an aquarium CO2 regulator and cylinder. Constructed from high-quality materials, using a permaseal will ensure that there are no more leaks and will void the use for plastic nylon CO2 o-ring washers. Using a CO2 Brass Perma-Seal will ultimately reduce countless costly refills and will allow aquatic plants to fully benefit from a continuous supply of CO2 in a planted aquarium tank.