Zipp Vuka BTA Water Bottle Cage – Carbon Black. Designed and engineered specifically for the Vuka BTA mount the Zipp Vuka Carbon BTA bottle cage is engineered to virtually eliminate any unwanted bottle launch.Designed and engineered specifically for use with the Vuka BTA mountConstructed completely from unidirectional carbon fiber for lightweight and strength as well as super secure bottle fitEngineered to virtually eliminate any unwanted bottle launch.