A surgical instrument used to restore the anatomical and mechanical axes during orthopaedic correction osteotomies. It is typically designed as a robust block with a long, thin, adjusting rod running through its centre and an incremented measuring scale that enables the surgeon to gauge the adjustments made to the axes (the medialization). It is usually attached to a dedicated bone plate which is bridging the osteotomy site in order to achieve the correct offset of the two separated bone sections. It is typically made of high-grade stainless steel and can be used on adult and paediatric patients. This is a reusable device.