Ok, I know what you are talking about.
The actual name is the Type 021 missile fast attack craft (FAC) (NATO codename: Huangfeng class). It is a Chinese copy of the Soviet Osa I class boat, and over 105 were built. The Chinese have mostly retired this type by the 1990's, but they are still in service with Yeman, North Korea, Pakistan, Bangladesh, and Iran. In the 1990s Jiangnan Shipyard (the maker of the type) also developed few improved variants, codenamed as Hounan and Houdong class by Western intelligence, for export market. Some of these boats are armed with the improved YJ-8 (C-801) series anti-ship missiles to replace the original SY-1 (SS-N-2 Styx). A variant known as Hola class with six missiles was introduced in 1970 with only one unit built.
The design has a standard displacement of 205 tons, is about 39m long, has a beam of 7.6m, and a draft of 3m.
The design is really dated, especially if it has the the original SY-1 (NATO codename Silkworm) missile... but still a threat nontheless.
Next time, post the entire name of the type, as what gave the answer away to me was both the Type 21 and the OSA 1 Type designation. That indicated a missile boat, possibility of Soviet origin.
Edit: To give you an idea of what they look like, here's a few pictures: