Vertex Pro forged piston:

Vertex Pro forged pistons (high-quality steel) are fitted as standard to a large range of motorbike brands.
The manufacture and anti-friction treatment of forged Vertex Pro pistons offer a longer lifespan, better engine response and reduce the risk of seizure.
The Vertex Pro forged piston is an essential component for off-road bike maintenance and repairs.
Replacement piston ring product no. 266990
The piston kit includes :

• 1 piston size C diameter (87.98 mm)
  
• 1 gudgeon pin
• 1 set of piston rings
• 2 circlips

(Actual product may differ from photo)