- Derailleur brands: Vision
- Themes: Ultra-lightweight - road racing models
- Country: Taiwan
- Date of introduction: 2016?
- Date of this example: unknown (coded 4116, which might possibly mean week 41 of 2016 - but may not!)
- Model no.: VT801
- Weight: 176g
- Maximum cog: 25 teeth (source: Vision, although they claim that the nearly identical VT800 can accept a 28T sprocket)
- Total capacity: unknown
- Pulley centre to centre: 62mm
- Index compatibility: 11 speed
- Chain width: 3/32”
- Logic: top normal
- B pivot: sprung
- P pivot: sprung
- Materials: Mainly carbon, with an aluminium b-knuckle and inner pulley cage plate.