Circlips tend to have open ends rather than making a complete circle. The open ended design gives the circlips a spring pressure effect. Once fitted in place, the spring effect ensures that they do not move or slip.
Many circlips have a small hole at either end. This allows for the installation or removal of the circlip pliers. Normally, specialised circlip pliers are used for this. They have specific sized tips that fit into the small holes within the circlip.
E type circlips, or E-Clips are also very popular. They do not require installation with specialised circlip pliers and are mounted radially, rather than axially. They are easy to remove and install.
Internal and External circlips
Depending on the application, you will require either an internal or external circlip: