Boeing 737 models have gone through 4 types of winglets: Mini, Blended, Split Scimitar, and Advanced Technology for the MAX.

Winglets are used by airlines for a good reason — they save companies money by allowing airplanes to fly more efficiently, ...

Southwest Airlines has ordered split scimitar winglets for 85 of its planes ... and a large ventral strake." 52 Boeing 737-800s will be retrofitted with the scimitar winglets.