Your search for "punching-bags*" revealed the following:
Bag/Fc Weight Disc Hook
• Uses your existing weight discs • Portable and easy to install • Use for punch bag or floor-to-ceiling ball tie down
$30.00
Bowed Shackle And Swivel
• Use for mounting punch bag
• Increases lifespan of D shackle and belt by reducing wear
$30.00