This Extensometer is ideally suited for testing anisotropic materials such as advanced composites as well as for general purpose tests like determining Poisson ratio. Model 3560BIA uses a design unique, where the knife edges remain parallel during the displacement. This approach greatly reduces crosstalk between axes and allows use on round or flat specimens with equal ease. These Extensometers are very easy to mount, integral springs hold the unit on the test sample. The parallell multiple flexure design makes these units very durable.