There are two structure models of annular BOP, model A: tapered rubber; model B: spherical rubber.
Upper housing and the body have two connection forms as connection by bolts and connection by claw chuck. Annular Blowout Preventer with spherical rubber is composed of five parts as upper housing, body, piston, spherical rubber, and anti-dust ring.

Annular BOP with tapered rubber is composed of seven parts as upper housing, wear plate, body, piston, tapered rubber, anti-dust ring, and supporting cylinder.
Specifications and technical parameters of Annular Bop (Model A)