Starlock Multitool Adapter™ (Screw-System) - Oslo Tool Company Int.
Multi-Tool blade to OIS adapter kit | eBay
Amazon.com: Bosch 2609256983 Adapter : Tools & Home Improvement
Ocillating Multi Tools Shank Adapter For All Kinds Of Multimaster Power Tools Ois Starlock Oscillating Saw Blades Adapter - Power Tool Accessories - AliExpress
Fein Starlock Oscillating Multi-tool System Explained