Unused surplus Swagelok (Nupro) Poppet Check Valve in original packagingSS-4CA-VCR-3SS-4CA-VCR-50 Technical Specifications: Adjustable Pressure, 1/4 in. Swagelok VCR Fitting, 50 to 150 psig (3.5 to 10.4 bar) or 3-50 psi (.21 to 3.5 bar).