AVETCO schematic showing a D-ring measuring 21.3mm by 29.13mm outer size and 15mm by 23mm inner size.

AVETCOs diagram of a heavy duty D shaped ring with a 3mm 011 thickness The outer dimensions are 213mm L and 2913mm W and the internal space measures 15mm L by 23mm W Precision labeling and directional arrows are used for dimensional reference