Here the approximate inner dimensions: 15,5x11x4,5cm
For comparison, the popular Garmin Navi 2597 folgede Dimensions: 13.7x8.3x1.9cm,
TomTom Go 500: 14.45x9.05x2.22 cm
Becker Ready 50: 14x9x1.7cm.
Length and width are OK, but the Becker eg fits almost three times purely ...
If you want to Navi take the manual, or other accessories, the bag might make sense. Otherwise unfortunately s largest fall.