Sa'ar 4.5 (Hebrew: סער 4.5) is a class of Israeli Sea Corps missile boats designed and built by Israel Shipyards Ltd. as an improved and stretched Sa'ar 4-class missile boat. There are two different subclasses that are both named Sa'ar 4.5. The first subclass was initially called Chochit (Hebrew: חוחית), but renamed to Aliya (Hebrew: עליה). Two Aliya-subclass boats are in service with the Mexican Navy. The second subclass was initially called Nirit (Hebrew: נירית) but renamed to Hetz (Hebrew: חץ). Eight Hetz-subclass boats are in service with the Israeli Navy.