Project Zomboid Now Early Access on STEAM
Tweezers have very little use, being that they're only used to remove glass shards and bullets. In single-player they are mostly useless since the player cannot be shot, whereas glass shards can become lodged by climbing through a smashed window.
Tweezers are fairly common and can be found in medicine cabinets and first aid kits.
From newitems.txt (Project Zomboid directory/media/scripts/)
Weight = 0.1,
Type = Normal,
DisplayName = Tweezers,
Icon = Tweezers,
Tooltip = Tooltip_UseOnHealthPanel,
General First Aid