Most Ultra-Drain Guards are held in place by pinching the material of the unit between the storm drain's grate and the catch basin. The advantage of this is that it's simple. Lift the grate. Place the Drain Guard. Lower the grate. Done. The one consideration with this type of setup is what happens to the installed Drain Guard when the grate is lifted? Well, if you don't plan ahead and use the built-in lifting straps, it's going straight to the bottom of the catch basin. Ultra-Drain Guard Retainers eliminate that issue. These steel bars span the opening of the catch basin and secure the Drain Guard whether the grating is in place or not.