April 29, 2015 1:19 PM EDT

Spectators at the London Marathon this past Sunday may have been surprised to see a pair of giant testicles bobbing up and down among a sea of runners. But Jack Woodward’s reason for dressing as male genitalia is as serious as the costume was absurd. Woodward, 22, decided to don the costume to raise money and awareness for testicular cancer, to which he recently lost his 21-year-old friend Rob Harris.

Woodward ran not just as any pair of nuts, but as Mr. Testicles, the mascot of the Male Cancer Awareness Campaign. The friendly mascot exists for the purpose of “reducing embarrassment and raising awareness of testicular cancer,” which has a good prognosis if detected and treated in the early stages.

Woodward told BBC’s Newsbeat, “I think too many people are too self conscious to go and get checked or they find something and then they just brush it off. But instead if you find something irregular with your body or different you should just go get it checked, it’s better to be safe than sorry. “

Write to Eliza Berman at eliza.berman@time.com.

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