This is a hose clamp used in Lycoming piston aircraft engine assemblies to secure flexible hoses to rigid fittings and prevent fluid leakage. The clamp is typically found in the oil sump and induction system where it maintains a tight seal around intake or oil hoses, ensuring reliable pressure containment and prevents line detachment under vibration or pressure pulsations.

It’s a small yet critical retention component designed to fit specific hose diameters and is often specified directly in engine parts catalogs for models like the O‑360 and O‑540 series.