RAM® 角柱クランプベース（幅2.5インチまでの支柱用、金具なし）

I mounted my GPS to a square tube on the boat and the rubber ball grips it securely without any slipping even in rough water. The 1.5" ball connects perfectly with my existing arm, making it a simple upgrade.

Needed a sturdy clamp for my square railing, and this base’s 1.5" ball locked in perfectly without any wobble. Just wish it came with the hardware, but that’s easy enough to source locally.

Finally, a mount that actually fits my heavy-duty square posts without any wobble. The 1.5" ball locks in place securely, and I appreciate that the clamp opens wide enough for a 2.5" post. Just wish they included the hardware, but it was easy enough to find at the local store.