Find it here - https://doublemdefense.com/product/magpul-qd-paraclip-adapter/

Factory New.

UPC: 873750011851
SKU: MAG542

The QD Paraclip Adapter fits push-button QD swivel sockets to allow use with Paraclips and other clip-in sling attachments. Made from precision-cast Melonite finished steel. Made in U.S.A.