Vintage Boring Head Jig Boring Fly Cutter 3/4" Shank 3" Diameter Adjustable. This is an older boring head that looks to take the 1/2" square bits. I lightly cleaned and lubricated. Looks like it may have had a makers mark possibly on pic 7. Unfortunately, I couldn't make anything out. Length of 3/4 portion of shank is approximately 2". Shank then transitions to approximately 1 1/2" diameter with a length of 2". I haven't personally seen this style before and couldn't find any others on ebay. If you have any information I can add to listing please feel free to message me. Please review all photos to determine condition and identification. Item is sold as is with No Returns. Will be shipped via USPS Priority.