L+-Curl lashes are good for countering the effects of downward-pointing lashes. They are also very effective for deep-set eyes and monolid eyes. They have the most pronounced curl of any of the extension lash types.
Just as with D-Curl lashes, L+-Curl lashes are only suitable for attaching to natural eyelashes which are themselves quite curly. They will not bond strongly with naturally straight lashes, because the curl means there is almost no shared surface area for the glue to attach to. So, if you try to use them with naturally straight or mildly curling eyelashes, there’s a risk of the extensions falling off early, rather than clinging to the natural lash until it falls out naturally.