/ Precision Measuring Tools / Precision Hand Tools / Bore Gages / Bore Gage Accessories / 78/782F * Not actual product image 65484 78/782F Extensions for 781XT AccuBore Electronic Bore Gage 65484 Other similar products The Starrett Internal Extensions for 78 Series Internal Micrometer includes 1/4-5/16" (6-8mm) sizes, 2.5" extension size, and fits models 78XT/780XT/781XT-312-375. Extension 2.5"/63mm Long for use with 78/780/782, 312-375. Features Specifications Contact Starrett Features Extensions can be added to both the 780XT and 78XT Series, enabling internal measurements in deep hole bores. (Multiple extensions can also be used.) 2.5" Length Specifications Fits Starrett Series: 78XT/780XT/781XT/782XT–312-375