Liqui Moly DEF Anti Crystal Additive Concentrate is designed to prevent malfunctions in SCR systems of diesel engines. It reduces deposits in the AdBlue tank and AdBlue injection system by ensuring fine atomization of the urea solution. This additive minimizes the risk of AdBlue crystallization, guaranteeing optimal return flow. It is suitable for all SCR systems using 32.5% urea solution (AdBlue, DEF). For best results, add after filling the AdBlue tank. The recommended dosage is 0.25% to the AdBlue solution (1:400). 25ml treats 10L of AdBlue, 250ml treats 100L of AdBlue, and 2.5L treats 1000L of AdBlue. This is for long-term application and should not be added to fuel.