Weidmueller SDQ T HANDLE HEX 5

SDQ T HANDLE HEX 5 likely refers to a hex key (Allen wrench) with a T-handle. "SDQ" is likely the brand or product line. "T HANDLE" clearly indicates the tool has a T-shaped handle for better grip and torque. "HEX 5" refers to a 5mm hex size.  Therefore, this is likely a 5mm hex key with a T-handle.