This adaptor allows professionals using Hilti core drilling rigs to convert proprietary quick-disconnect systems (BI, BL, BU) to the universal 1 1/4" UNC male thread. It lets you use competitively priced, standard core bits from any manufacturer, reducing tooling costs without sacrificing performance. Made from heat-treated, high-speed steel, it provides a secure, wobble-free fit and reliable operation on demanding jobs an essential accessory for maximizing versatility and efficiency.