This reversible rubber/metal set of 3 spiked feet is supplied with a dedicated fixing tool. The spike is made of a special hard anodized aluminum alloy extremely resistant to corrosion. These are designed to fit the Manfrotto 441 and 190MF4 tripods. Attachment: 11.6mm hole three- faced; color: black; material: technopolymer; material - screws and fixings: Stainless steel; weight: 0.49 lbs.