Designed for BCD inflation, deflation and float adjusting airway 1 inch inner diameter, 16 inch long hose fits 30 lb BCD wing or jacket BCD; 19 inch fits 50 lb / 65 lb double BCD wing and jacket BCD 16 inch corrugated hose fits 30 lb backplate donut wing; 19 inch fits 50 lb / 65 lb double cylinders backplate donut wings 3/4 inch inner diameter, 14 inch hose fits XSS jacket BC; 16 inch for ML jacket BC; 18 inch for XLXXL jacket BC Use scenarios Dive or rental fleet setup: Use the 16 inch straight hose for 30 lb wings or jacket BCD and the 19 inch straight hose for 50 lb / 65 lb double wings to cover common configurations; use the 16 inch corrugated hose for backplate donut wings and the 19 inch corrugated hose for backplate donut wings with heavier cylinders. Field maintenance or gear upgrades: or extend hoses for backplate donut wings with the appropriate corrugated hose length (16 inch for lighter systems, 19 inch for heavier systems) to ensure proper inflation, deflation and buoyancy control. Travel or training environments: Prepare jacket BCs across sizes XS to XXL using the 3/4 inch ID options (14', 16', 18') to match the diver's jacket size and preferred hose length.