RAM® 球體轉接器，附 3/8 吋-16 螺紋柱與防鬆墊圈 - B 尺寸

The threaded post was exactly 0.5 inches as described, so it mounted flush without any extra spacers. I've used it with a couple different arms and the ball locks in tight with zero wobble.

The rubber ball is a perfect 1-inch fit for my existing arms, and the half-inch thread grabbed cleanly with the lock washer doing its job. Took maybe two minutes to swap out and it's held rock-solid on a bumpy road since.

I needed a replacement ball for my GPS mount, and the 3/8"-16 thread matched perfectly with my existing RAM arm components. The lock washer is a nice touch that keeps everything tight. Works exactly as intended.