CHRISTIE SECURITY BRACKET ACCESSORY FOR SUBWOOFER
https://shop.cinemanext.com/shop/p004456-christie-security-bracket-accessory-for-subwoofer-4765
https://shop.cinemanext.com/web/image/product.template/4765/image_1920?unique=d076434
CNX-PID P004456 MPN 145-110103-01