2-1/4" Brass Clamp-On Shade Fitter - fits sockets 1.5" diameter
Comes with 3 set screws and 1 attaching screw.

Each sale comes with 5 units and associated screws sets, ideal for dealers that recondition, repair, or retrofit old lighting fixture. These sets are bulk packed by the manufacture.

Outer ring: 2.36 inches
Inner Ring: 1.28 inches (expands) 1.40 inches
-Designed to fit a 1-1/2" socket with lip (see 4th picture).