This is a guess, but those look like the standard synthetic rubber grips that Hogue offers for the S&W 3900 series compact single stack series. I think their model number is 13010, usually many of them listed on the big auction site in the $20 range. The labels on the last pack I bought says "Recoil Absorbing Rubber Automatic Pistol Stocks Hogue" "S&W 3rd Gen. 3900 series Decocker on Slide". Hope that helps.