If you have small arms or just want to keep your arms free while running or working out with your Pixel 3a, the Sporteer Zephyr Runner's Belt is the ideal option.
The Zephyr is ultra-thin and lightweight but has plenty of room for your Pixel 3a (with or without a case) and cash, cards, ID, lip balm, or gel shots. A water resistant layer inside the pocket isolates your phone and protects it from sweat, moisture and scratches. And, you'll always have full access to your apps and screen controls through the touch-sensitive screen.
The Zephyr running waist pack fits Google Pixel 3a with no case or cases up to 160 x 85 x 12 mm.