Paralympic champion Jon-Allan Butterworth has announced his retirement from professional cycling at the age of 34.
Butterworth was part of Great Britain's successful mixed team sprint squad at the Rio Paralympics in 2016 alongside Jody Cundy and Louis Rolfe, adding to his haul of three silver Paralympic medals, all won in London in 2012.
The former RAF weapons technician joined British Cycling after a Paralympics GB talent ID day in Loughborough, just 10 weeks after having his arm amputated due to injuries suffered in an attack at the Basra Air Station in August 2007.
Within two years he set a world record for the C5 kilo at his debut UCI Para-cycling Track World Championships event in Montichiari, Italy in 2011, the first of 10 world championship medals that included four golds.
"I have enjoyed a long and successful career on the Great Britain Cycling Team," said Butterworth.
"My proudest achievement is becoming the first British ex-serviceman to win a gold in Paralympic history. I have had the pleasure of working with some truly amazing people who have helped make it all possible.
"On reflection at the end of this strange year, the time feels right to retire from professional cycling so that I can focus my energy on the next step of my career.
"I wish my team-mates all the very best in their preparations for Tokyo 2021 and I thank them for all the memories."