He said New Zealand's two hockey goalkeepers - Kyle Pontifex and Bianca Russell - would be sporting OBO equipment in London.
Pontifex also works part-time for the company, which employs 14 staff, providing player feedback.
Research and design takes place in OBO's laboratory, which features technology that takes video footage at 22,000 frames a second to capture the impact of a hockey ball hitting a dummy's head.
Barnett said the fact that most teams did not have back-up goalies these days was a good sign that the equipment worked. "In the old days, [teams] would definitely have taken two goalkeepers, but goalies just don't get injured as much as they used to because the protective gear has improved so much."
Barnett said that when he established OBO protective pads were commonly made out of cumbersome materials such as leather and bamboo.
The New Zealand firm began experimenting with much lighter closed-cell foam, he said.
"We didn't invent [the use of] closed-cell foam but what we did do was take what was already being done by one or two companies and do it a lot better."
Barnett said OBO's core products, including leg guards and hand protectors, were manufactured in Palmerston North, while other products such as helmets were made overseas.