AI says

Based on the specific scale, the short mainspring profile, and the positioning of the alignment pin hole, these specific stocks fit one of two iconic revolver classes:Smith & Wesson J-Frame Round-Butt (Most Likely): This includes ultra-popular snub-nosed pocket revolvers like the S&W Model 36 (Chiefs Special), Model 60, or Model 642. The compactness of the grip matches J-frame proportions perfectly.Smith & Wesson K/L-Frame Round-Butt: Such as the S&W Model 19, 66, or 686 variants featuring a round frame.

I don't know anything else about them, the box has no label