K2609A 3/4 to 3/8 C-Shaped Torque Adaptor Extension Aviation Tool NOS.  This is a specialty tool that I wasn't able to find much information on.  The only places that had this listed by request only is aviapool and mfsupport.  Both have it listed as 3/8 Ext Sq 3/4 Sq Dr Trq Adptr.  Possibly made by Snap On or ATS division.  Most likely used on large turbine engines.  Please review all photos to determine condition and identification.  Item is sold as is with No Returns.  Will be shipped via USPS Priority.