Surgical and medical apparatus and instruments namely, stent and stented valve loading units, and parts and fittings therefor; cardiac apparatus and instruments for use in cardiac valve replacement procedures and parts and fittings therefor; cardiac valve replacements apparatus; aortic valve repair and replacement apparatus; catheters; tips for catheter delivery systems; handles for manipulating catheters; handles for catheter apparatus; handles comprising of multiple parts for catheter apparatus; cartridges for carrying medical prostheses; parts and fittings for the aforesaid apparatus.