This D0201.16 Hose Clamp from Manfrotto is for Gitzo microphone booms, monopods, and tripods. It comes in two parts, and guides the leg sections preventing one section from separating and pulling all the way out of another section. This is included with the compatible gear, and is sold here as a spare or replacement part.
Reviews Gitzo D0201.16 Hose Clamp for Select Gitzo Microphone Booms, Monopods, and Tripods