Buy from Amazon.com : https://www.amazon.com/gp/product/B00004T7R4?tag=thefithousewi-20<br /><br /> General Tools 520 Precision Adjustable Trammel<br /><br />Product Description : <br />The General Tools and Instruments 520 Adjustable Trammels draw large circles and measure sizable distances with the accuracy of a divider<br />Fine adjusting screw sets points accurately points are removable and may be replaced with the pencil holder<br />Die-cast bodies with hardened and grounded steel<br />3-Inch 76mm needle-point legs clamp opening for beam is 38-Inch x 34-Inch10 x 19mm<br />Trammels conform to government specifications GGG-T-661b
