1.The 1/2 npt air line fittings are primarily made for air and water (No Freezing). Other fluid types are highly prohibited.2. The use of 8mm pneumatic connector is limited to areas that are highly prone to fire outrage3. Don't use the pneumatic air line 8mm connections in areas whose water temperature is above 60'C4. To avoid leakages and damage,you're advised to resist the temptation of adding extra loads to the 1/2 push lock fittings USER GUIDE5.Carefully examine the 8MM tube fitting ends for a right angle cutting. Don't also forget to check the external 1/2 npt air tube connectors surface for any scratch.6.Pneumatic composite should not be used for live swivel applications.7.8mm air hose fittings Body and collar are made of Nylon 6.6, gripping ring is stainless steel, and D seal and O-rings are Nitrile.