A 78 mm wide smartphone fits on the gimbal, as it is designed for devices with a width of 67 to 84 mm. The 17MAXpro with a width of 78 mm is therefore within the compatible range.
The gimbal supports smartphones with a width of 67 to 84 mm, a thickness of 6.9 to 10 mm and a weight of 170 to 300 g.