A backplate and wing (often abbreviated as BP&W or BP/W) is a type of scuba harness with an attached buoyancy compensation device (BCD) which establishes neutral buoyancy underwater and positive buoyancy on the surface. Unlike most other BCDs, the backplate and wing is a modular system, in that it consists of separable components. The core components of this system are:

• A harness, which attaches the system to the diver, and may support other accessories.
• The backplate, a plate, usually made from metal, which is held against the diver’s back by the harness, and to which the diver’s primary cylinder or cylinders are attached.
• An inflatable buoyancy bladder known as a wing, between the backplate and the cylinder(s), used for adjusting the buoyancy of the diver when in the water.

A backplate and wing (often abbreviated as BP&W or BP/W) is a type of scuba harness with an attached buoyancy compensation device (BCD) which establishes neutral buoyancy underwater and positive buoyancy on the surface. Unlike most other BCDs, the backplate and wing is a modular system, in that it consists of separable components. The core components of this system are:

• A harness, which attaches the system to the diver, and may support other accessories.
• The backplate, a plate, usually made from metal, which is held against the diver’s back by the harness, and to which the diver’s primary cylinder or cylinders are attached.
• An inflatable buoyancy bladder known as a wing, between the backplate and the cylinder(s), used for adjusting the buoyancy of the diver when in the water.