This is the MotoTec Replacement J.Costa 34mm GLIDING ROLLER WEIGHTS Set of 16, 184-21-15.5g have smooth movement, high heat resistance, and exceptional durability due to their construction of polymer plastic compounded with Kevlar and carbon fiber.

Product Specifications:

• SKU: 184-21-15.5g
• Size: 34mm (Length)
  
• Outer Diameter: 16.4mm
  
• Set of 16
  
• Exceptional Heat Resistance
  
• Low Friction/Low Wear