Inner diameter 46.4 mm ,thickness 15mm .It can hold normal M42 extension tubes with 46 mm~46.3 mm.Or the 42 tube we special made for this clamp.Tools
Williams PL-46C 6-Inch Industrial Grade Diagonal Cutting Pliers
Industrial Grade Diagonal Cutting Pliers With Safety Ring
Tube clamp - Double Swivel 33,7 mm Typ 46 Cast iron
WeMacro rail and accessories – Wemacro Rail
Case Construction Clamp Hose 9706924
4 x 3 Concentric Reducer Grooved Fitting 316 Stainless Steel
ULTRAMACRO UM1209C PROFESSIONAL Grade Raynox DSLR Objective Extension Tube £408.00 - PicClick UK
Tube clamp (46C) – Wemacro Rail
Malleable Iron Key Clamps Pipe Fittings Supply