Prime Direct Stem Computer Mount | Computer Accessories | wiggle.com
AliExpress
BarFly Direct Stem Mount Fizik and 3T Garmin | Tree Fort Bikes
Amazon.com: Bike Computer Mount Bracket Compatible with Garmin/Wahoo/Bry ton Adapters with Go Pro/Flashlight Mount Out-Front Handlebar Bracket Fit for T rek 3T Stem Bar : Electronics
Universal Cycles -- Garmin Integrated Edge 3T Stem Mount [010-11807-30]