8 Pack Universal Metal Rings Sticker Compatible with MagSafe Magnetic Wireless Charger iPhone 17/16/15/14/13 Pro Max Mini, 2 Styles Ultra-Thin Notched and Round Ring Car Charger Kit (NO Magnet)

The black ones do stack but I also stuck a metal ring on the back of the bottom one for a stronger connection. It already had a gap in the circle but I had to trim a bit on each side to clear the hinge ETA: https://a.co/d/04faf8u7