HAJXZH 6 Pack E26 Light Socket Rings Lamp Shade Collar Retainer Ring for Light Fixture Lamp Lock Socket Replacement Adapter Ring with Diameter of (32mm) 1-3/8 Inches Black

I assumed all standard lamp bases were the same size. (I know, never assume). And my measurements matched the product description. However, the inside threads were just a hair too small (tight) to screw over the threads on the bulb socket. All six retainer rings had the same problem. I thought I might have to return the items, but came up with a solution. I used a hacksaw blade to cut a slot in the retainer ring allowing it too expand slightly and it worked. The retainer ring fits snugly and holds the lampshade in place.