A circlip (a combination of ‘circle’ and ‘clip’, and pronounced thus), or snap ring is a type of fastener consisting of a semi-flexible metal ring with open ends which can be snapped into place, into a machined groove on a dowel pin or other part to permit rotation but to prevent lateral movement. There are two basic types: internal and external, referring to whether they are fitted into a tube or over a shaft. Circlips are often used to secure pinned connections. Circlips which are fitted may be removed with a pair of needle-nosed pliers or a special snap ring tool if the circlip is designed to include entry points for the pliers or tool. Alternatively, cautious leverage with a flat-headed screwdriver may be necessary in lieu of the correct tools or design of snap-ring