Check the listing for details. 10Pack 4mm Tube OD Brass Compression Sleeves Insert Brass Ferrule Fitting. Condition: New. Listed at 8.49 USD. This brass compression sleeves ferrule is widely used in hose connection for hydraulic and pneumatic systems, HVAC, humidifiers, etc., suitable for connecting hose tubing.Specification:Color: Brass ToneMaterial: BrassHole Inner Dia: 3.2mm / 0.13 inchHole Outer Diameter: 3.9mm / 0.15 inchSuitable for connecting 4mm(ID) hose.Total Size: 6.00 x 14mm / 0.24 x 0.17 inch (D*H)Packing List: 10 Pack x Brass Ferrule FittingsAdvantage:The brass ferrule insert fittings are made of brass, it is durable and reusable.These ferrules have a smooth surface and provide a good seal, providing a secure connection for hose connections.Instruction:Insert the hose with appropriate diameter into the brass fittingNOTE: Please confirm the hose size before purchasing.