CESS-002L Barrier Spade Fork to 1/4 Inch TS Speaker Cable Adapter (Large Spade): Amazon.co.uk: Electronics & Photo
Speaker cable connectors - ChordOhmic 4mm banana plug and spade connector - The Chord Company
OTOTEC 8Pcs U Fork Y Spade Speaker Connectors 4mm Copper Gold Plated Banana Plug Screw Lock Red & Black For Wire Adapter Signal Transmission : Amazon.co.uk: Electronics & Photo
Using Spade Terminals on your Speaker Cable - YouTube