Sika® Injection-125 MY is a single component hydrophobic hydroactive injection grout based MDI (methylene- diphenyl isocyanate) polyurethane. Sika® Injection- 125 MY has very fast reaction time. When Sika® Injection-125 MY reacts with water, it starts to foam and expand very quickly. As the grout reacts, it expands and stops the water leak within a very short period. Expansion ratio is dependent on the amount of water added to the resin mixture and the moisture level in the environment. It reacts to form a very dense and flexible material or to a flexible foam.