That'd be a Wallstrett II (or revision B) model.
Wallstreet I was 233, 250, and 292 if I recall correctly, and then WallstreetII (introduced in September of 1998) was 233, 266, and 300. They were replaced in May of 1999 by the Lombard Powerbooks at 333Mhz and 400Mhz.
-vasu