This set of 3 reversible rubber/metal spiked feet are supplied with a dedicated fixing tool. The spike is made of a special hard anodized aluminum alloy extremely resistant to corrosion. Designed to fit the Manfrotto 441 tripod. Attachment: 20.6mm hole three- faced; color: black; material: technopolymer; material - screws and fixings: Stainless steel; weight: 0.49 lbs.