OPTI-PROOF INTEGRAL WATERPROOFER 250ML - OPTIPROOF02 OPTI-PROOF is a plasticiser, waterproofing agent and salt inhibitor, all in one. - Waterproofs, plasticises and retards - Controlled dosage - Consistent mix design - Easy to use - No waste - 1 litre is equivalent to 25 litres of standard product - 250ml is equivalent to 6.25 litres of standard product