LITERALLY MEANS "FASTER." 

Unlock your fastest self in the Cloudspike Citius 2 and break barriers from 800m to 1600m. Engineered in collaboration with On Athletics Club athletes for lethal speed and precision, the Cloudspike Citius 2 combines Helion™ HF, a Pebax® hyper foam, for supreme energy return you can feel with a unique half-length Speedboard® that is a blend of fiberglass-nylon that catapults you forward. 

• UPPER: One-piece mesh is precision-tailored for breathability, minimalist weight, and locked-down racing support.
  
• Made of 100% recycled polyester.
• MIDSOLE: Helion™ HF ( 40% bio-based) utilizes Pebax® responsiveness in an extremely lightweight package. 
  
• Half-length fiberglass-nylon Speedboard® loads the foam to amplify energy return and provides optimal stiffness for toe-off propulsion. 
  
• CloudTec™ elements visually honor On's signature design heritage.
  
• The 20mm stack height is legal for World Athletics.
• OUTSOLE: Full length 6-pin spike plate delivers grip and power, with pins strategically placed for 800m-1600m events.
  
• Surface-gripping heel pad for unmatched traction in wet or dry conditions.