The Sticky Bottle - -17° Cannondale Hollowgram Knot bar stem system fitted with the integrated mount. Holds a cycling computer and all your devices below with the removable Gopro adapter and also
NOS Cannondale Hollowgram Knot Stem for SystemBar -17 Degree 100mm Missing Bolts | eBay
Cannondale HollowGram Knot Stem -6 Deg 90mm Black
REC-MOUNTS Cannondale HollowGram SystemBar KNOT/SAVE Combo mount CAADα+GP NEW 4573214175650 | eBay