[Clyderiver-78]

Measures 49mm from outside of upper lug to outside of lower lug.

By my definition of lug-to-lug distance which is outside of upper springbar hole to outside of lower springbar hole:

The Instinct measures 40mm:

HTH

So to be clear, the picture above is of a 40mm garmin Instinct? I am looking all over the web for the lug to lug for both 40 and 45mm models.