Born without the lower part of his left arm, eight-year old Juan Moyolema was thrilled to receive a new hand from a Madrid-based organisation that uses 3D printers to create tailor-made prostheses which it donates to people around the world.
With his sister and two brothers looking on, he tried out his new limb for the first time in the family living room, slowly flexing at the elbow to close the hand.
"It's going to help me pick things up, things like toys," he said, grinning widely, before tentatively shaking the hand of Guillermo Martinez, founder of Ayudame3D, the social entity that made the arm.
A former toy designer with a passion for 3D printing, Martinez, 27, began tinkering with the devices as a hobby.
But after a 2017 trip to deliver prostheses to an orphanage in Kenya's Rift Valley, he decided to dedicate himself full-time to the initiative and set up Ayudame3D.
"The five arms that I took (to Kenya)...worked so well, so perfectly that I asked myself 'How can I just stop here?'"
Four years later, the organisation has grown into an international entity that delivers 200 to 250 arms a year all over the world, free of charge, to anybody who requests one.
From his workspace in a converted shipping container crammed with dozens of printers, prototypes and off-cuts, Martinez oversees a team of six staff and multiple collaborators across the country.
Prosthetic arms, based around three core designs reaching to the wrist, elbow or shoulder and made of plastic, are Ayudame3D's main product, but it also produces other medical devices, toys and souvenirs it sells to generate income.
Martinez did not give an exact figure of how much they cost to make but said it's a tiny fraction of a traditional prostheses, which can cost up to $40,000. His organisation relies on donations and awards and also gives companies 3D printing courses.
In the early days of the COVID-19 pandemic when face masks were scarce and many health staff worked unprotected, the group manufactured and donated some 20,000 plastic face-shields.
Looking to the future, Martinez wants to expand Ayudame3D's reach and range of products, but said he is not very ambitious.
"We just want to help as many people as possible. If we are in 50 countries this year we hope to be in twice as many next year."