Gorgeous, these look like real gold lip pearl grips at a fraction of the cost, we used to sell the real ones decades ago, we have a reference.  Superior to other imitation pearl, these are carved from solid stock, hand polished, not cast or poured.  The medallions are antique bronze and look great.  Come with a screw of course.

If you're not sure if you have a J, K or N frame, just flip out the cylinder and it should be stamped on the inside of the frame. For additional Smith and Wesson model to frame information, see the list picture below.