hair roller
Instrument around which a lock of hair is wrapped to make it curl.
hair roller pin 
Pin stuck through the roller to hold the lock of wrapped hair in place.
roller 
Cylinder whose length depends on the length of the lock of rolled hair and whose diameter depends on the desired curl size.
wave clip 
Plastic pin with interlocking teeth used to secure a lock of hair.
bobby pin 
Bent filament with tightly closed arms; it is used to secure a section of hair by holding it firmly in place.
hair clip 
Metal pin with elongated jaws that is used during styling to separate out sections of hair not being worked on.
barrette 
Bobby pin with a clasp; it is used as adornment or to secure a lock of hair or the whole head of hair.
hairpin 
Bent filament with spread arms that is used to loosely secure a section of hair such as a chignon.