In this design the cod end mesh is turned through 90 degrees into T90 configuration. This is when normal diamond mesh is turned through 90 degrees to enable the meshes to stay more open while the gear is being towed.
T90 is good for releasing small fish. T90 meshes enable the meshes in the cod end to remain more open throughout the full tow. This allows the release of small fish of all species. the actual size released depends entirely on the size of mesh used. In traditional diamond mesh cod ends, as the catch increases the meshes close up more and reduce water flow through the cod end, T90 helps to improve the water flow keeping the cod end more stable. this results in less damage to the catch while in the cod end due to reduced movement.