Internal diameter is approximately Ø76mm in and Ø66.2 in with 2mm thickness.
+Ø66.6 in with 2.7mm thickness.
+Ø67 in with 2.5mm thickness.
Another type of HSW wall fastening.
Also added another pattern.
The author remixed this model.
Internal diameter.
Another type of HSW wall fastening.
Also added another pattern.