Flange Kits, Bolt Hole Size 1.75 in, Compatible Pipe Size 1 1/2 in, Compatible with Brand Armstrong, Compatible with Series 1050, 1060, Astro 2, E.2, S&H, Compatible with Series Family 1050, 1060, Astro 2, E.2, S&H, Flange to Pipe Connection Type FNPT, For Use With Potable Systems Yes, Flange Type Standard, Number of Mounting Holes 2