ONZ Sport: Flex Guards - Auckland FCRedefine Your Protection: ONZ Flex Guards Our Most Advanced Guard, Ever. The ONZ Flex Guards are our most protective, most technically advanced shin guard built for the athlete who refuses to settle. Where standard guards offer basic impact resistance, Flex Guards go further: engineered with a smart response compound that hardens on impact and flexes at rest, they deliver a level of protection that traditional guards simply can't match. Without the