The Paraball 10 lbs is the next step in the progression.  It is a great tool to train slams. however we recommend you do them on sand or grass first, before trying a hard surface. 

Ball Weight: 
10 lbs (4.5 kg)

Rope Diameter: 
0.5 in (12.7 mm)

Rope Length:
9 ft (2.7 m)