1 1⁄2” Slip x 50mm Slip Metric to Standard PVC Adapter. These adapters work great with our Shadow® Overflow for customers that want to use 50mm metric PVC or reduce down with metric PVC in international countries. Can also be used for our sumps as well. This slips into the rear fittings on the bottom of our Shadow® overflow. Then you can slip 50mm pvc pipe into the adapter.