This female-to-female adaptor joins a 1/2" BSP male thread (such as an extension rod or drill spindle) to a 1 1/4" UNC male thread, making it ideal for non-standard core drilling setups. Crafted from corrosion-resistant steel, it delivers a rigid, reliable connection. Precision-machined threads on both ends ensure a secure fit, efficient power transfer, and stable operation for demanding drilling tasks.