Cluster lashes, which are sometimes referred to as fans, flares, or flare lashes, are aptly named. These premade fans are exactly what they sound like: fake lashes packaged in a bundle with a few individual lash hairs. These can be used to thicken, volumize, and lengthen specific parts of the lashes, such as at the outer corner of your eye.
They are applied similarly to any other false eyelash, with a pair of tweezers and with lash glue.