The S&W99 has a trigger guard thats rounded at the front. The P99 has a squared trigger guard at the front that may not fit correctly in a S&W kydex. Just for infomation sake. I have an Uncle mikes Kydex made for a Springfield XD9. My .45 S&W99 fits perfectly in it. My .40 P990 fits but not as well. I could add some spacers and it would more or less work perfectly. I "believe" a 9MM P99 slide is a bit narrower than a .40.
Looked at it. Not bad I suppose, but I really would like to avoid holsters with rivet/bolt on belt clips if I can. One of the reasons I'm so big on Rocketman is that the holsters are one piece basically.