For quick removal/installation of valve collets with cylinder head in situ or on workbench. Remove/install by firmly pushing or tapping the tool with a hammer. The magnet in the tool captures the collets. Ideal for replacing broken valve springs or valve stem oil seals without removing the head from the engine. For use in situ, a suitable adaptor will be required to allow compressed air into the combustion chamber to hold the valve closed while compressing the valve spring. The Set also includes two valve lapping tools with wooden shafts and four sizes of rubber suction cups. Suitable for grinding most engine valves. Supplied in a storage case.