1/4"NPT Ports, Brass, Replaces SPC400BNext Day Fittings is an authorized Parker FRL Distributor. If you have any questions about the Parker FRL 003393001 Air Check Valves's technical information or availability please call us at: 844-323-8752Next Day Fittings is an official Parker FRL distributor, we can offer our customers the best pricing and factory lead times. Our trained and knowledgeable staff is always ready to help with any aspect of the Parker FRL product purchasing process. Whether you need assistance from a customer service agent or a product engineering expert, Next Day Fittings is your Parker FRL partner every step of the way.