The EcoTech Marine Thick Spacer for the MP40wQD is a replacement component designed for the QuietDrive version of the MP40 Vortech Pump. This thick spacer is intended for aquariums with glass thicknesses of 1/4" (6mm) or less. It ensures proper magnetic alignment and secure positioning of the pump, helping to maintain consistent flow and quiet operation. Ideal for thinner glass tanks, this spacer provides the correct spacing to prevent excessive pressure on the glass while ensuring optimal pump performance.