The Straps we offer fit "All Series" compatible with Apple Watch

Sizes:

-38/40mm

(Series 7) 41mm

S/M (8.05" ) or M/L (8.85")

-42/44mm

(Series 7) 45mm

S/M (8.25") or M/L (9.25")

S/M = Small/Medium or M/L= Medium/Large