Aquatemp Brand Uni-Nut Heater Unions (Small)

For heater tubes with 1 5/8 and 1 7/8 inch outside diameter. Use a caliper to verify tube diameter if unsure. Not a replacement for 'split-nuts' .Sold in a pair as nut and retainer ring to repair/replace cracked or broken pieces. Nut installs first, then retainer ring is split open and forced over tube flange to allow nut to pull against flange. recessed notch on ring faces nut.