Expansion Joint, Bolt Circle Diameter 3 1/8 in, Bolt Hole Size 1/2 In.-13, Bolt Hole Threading Threaded, Burst Pressure 853 psi, Compression Distance 1/2 in, Connection Type Flanged, Expansion Distance 3/8 in, Expansion Joint Type Single Bulb, Features Absorbs Pipe Movement and Stress, Flange Diameter 4 1/4 in, Flange Material Steel, Flange Material Finish Zinc-Plated, For Fluid Type Air, Gas, Hydraulic Fluid, Water, Joint Material Neoprene, Joint Material Finish Not Applicable