A set of shear pins for the knife hub is sold here Husqvarna RB150 or RB180 lawn tractor Contents of a packaging 4 individual pins. If you are not sure whether these shear pins fit into your mower, simply write an email. If you have problems identifying your tractor, I would be happy to help you. I check that and then tell you Notice. Dimensions: 6mm x 8mm Height approximately 13mm More Husqvarna Please spare parts on request.