Why does the west call China's C-20 1 anti-ship missile a silkworm missile?

C-20 1 is the first generation anti-ship missile developed by China. YJ-2 series, C20 1 anti-ship missile, total combat weight: 2000 kg, range: 150 km, warhead weight: 500 kg.

C20 1 anti-ship missile, model characteristics, C-20 1 is the first generation anti-ship missile developed by China, also known as Yinghai-1 and upstream-1 missile, which is called silkworm missile in the west and copied from Russian SS-N-2 Styx anti-ship missile. The improved version includes Yinghai -2/3/. After more than 20 years of development, a huge seahawk family has been formed, including shore ships, ship-to-ship missiles and air-to-ship missiles. 1972 is equipped with troops, and the export type is called Longfei -3(FL-3).

Type C-20 1: the length of the projectile is 6.6m, the diameter of the projectile is 760mm, the wingspan is 2.4m, the takeoff weight is 2658kg, the warhead weight is 5 13kg, and the charge is 380kg. The latest improved Yinghai -4 adopts solid booster and turbojet engine, with the launch weight reduced to 2000kg, the maximum range increased to 150km, the missile length 7.36m, the missile diameter 760mm, the wingspan 2.4m, the effective combat range 35- 135km and the flying height 70-200m m.. It uses cruise inertial guidance and terminal radar. The extended range of Seahawk -4 is increased to 200 ~ 300 kilometers, which can be launched on land or in the air.