This is a replacement Arrma Differential Gear Set.

Features: 

• Super-tough and durable steel to withstand extreme RC action 
  
• Precision manufactured Gear Teeth for consistent performance in all conditions 
  
• Metal Cross Shafts for long-lasting durability and super-efficient running at high speeds

Includes: 

• (4) 10T Satellite Gears
• (2) Metal Cross Shafts
• (2) 20T Planetary Gears
• (4) Satellite Gear Shims
• (4) Metal Cross Shaft Insert