17mm ball attachment for bike navigation systems Garmin Yupiteru RWC and Dynojet Power Compatible with A28 [REC17-A28] (ZUMO), (ATLAS), (X-RIDE),

The first image shows all accessories. This product is for 17mm only (if it is 16mm or 18mm, or if it is even 1mm different, the ball will move and it cannot be used). Please check the dimensions of the parts currently attached before purchasing. This product (holder attachment) cannot be used alone. Arm parts and joint parts are required. Please read the product description (this is the detailed section). If you are using a computer, please click on "See more".