After purchase, I did a temporary assembly, but the cycle computer was difficult to see, so I bought a longer type. The included Garmin mount is unused. Brand: Rec-Mounts * Aluminum machined conversion adapter compatible with GoPro cameras, mountable on adapters. * Type: HED4 Straight C-C 30mm * Adapter material: AL6061 Aluminum CNC machined * Socket material: Resin * Conversion adapter weight only: Approximately 15.4g (excluding socket + screws, about 4.6g) * The 0mm socket (base plate) can be replaced when changing models. * Compatible cycle computers (as of September 22, 2021): Garmin: Edge 20/25/130/500/510/520/530/800/810/820/830/1000/1030, etc. (Supports J and PLUS at the end) * Other: Can be changed to the sister brand (Rec-Mounts Plus) 2-stage lock base parts set [R+HED-Repair]. Smartphones can also be attached (dedicated cases required). Thank you for viewing.