This ring comes from GepRC and it's one of those products in the industry that is unusually good similar to the Bee Brain V2 from NBD. It's not the most protective or the most durable but it's quite good at being resilient given it's low weight of only 13g per set. Weight is the biggest enemy especially on the ends of the arms. Because of the low cost and performance of these guards, it just doesn't make sense to reinvent the wheel. To be absolutely clear, this is not a duct. It is only a guard. That being said, it does have some minor duct-like effect because of the roll at the edge of the rim. Specifications: Polycarbonate material ~61.5mm OD ~54.5mm ID ~3.25g per duct 9x9mm M2 mounting pattern 2mm thick mounting base - can be mounted under motor or under arm Top of guard ring is 20mm above top of mounting base Guard ring is 7mm tall
