Black Square Plug: 3-1/2", 125 psi, Threaded MPN:0319902680

Relton's premium black square plug offers superior strength and longevity with a durable construction, perfect for use across a wide range of industrial applications such as HVAC systems, compressed air equipment, and more. Its precision engineering ensures reliable sealing performance while its 125 psi rating offers high-pressure capability. The black color allows for easy identification and tamper indication while the square design provides universal compatibility with threaded fittings. Whether working in commercial, industrial or residential settings, Relton's black square plug delivers consistently high-quality results without compromise.