Amazon.com: Ramtech Adjustable Bike GPS Handlebar Mount for Bicycle + Bonus Wrist Strap, Compatible with Garmin inReach Explorer+, SE+, Spine Mounting Adapter on Mini, Mini 2 (Won't fit Directly to Minis), BHM :
Bracket base for Garmin OREGON 450/ OREGON 550/ OREGON 400T/ OREGON 550T Bicycle GPS navigator bracket base and tie Fixed belt - AliExpress
SUCTION CUP MOUNT HOLDER FOR GARMIN OREGON 450 450t 550 550t 300 400c 400i 400t - Walmart.com