These tools fit 6 different sizes of flywheel rings - M10 (10mm), M14, M16, M18, M24 & M27 M24 X 1.0 Pitch Right Hand Thread Male M27 X 1.0 Pitch Right Hand Thread Male M10 X 1.25 Pitch Right Hand Thread Male M18 X 1.5 Pitch Right Hand Thread Male M14 X 1.5 Pitch Right Hand Male M16 X 1.5 Pitch Right Hand Pitch Male The tapered lock lock type rings cannot be removed without the use of this specialised tool