The UM5001 U-mount Universal Round Mount from On-Stage handles round surfaces from 21mm to 30mm in diameter. The U-mount works directly with TCM9163 or TCM9263 Snap-On u-mount systems (sold separately), allowing use on round surfaces such as microphone stands and shopping carts.
On-Stage UM-5001 Specs
Snap-On Back Cover iPad 2, 3 or 4: TCM9163
Snap-On Back Cover iPad Mini: TCM9263
U-Mount Universal Mounting Post Accessory Kit: TCA1066