Our 3K and 4K carbon fiber trombone cases. Inside material/padding is the same in both cases.
The 3K case is black. Tenor weighs 7.4 lbs and the bass 8 lbs empty.
The 4K case is blue. Tenor weighs 6 lbs and the bass 6.8 lbs empty.
Bass travel case 11.2 lbs empty.