The CIRS Model 066 Prostate Elastography Phantom is a disposable phantom developed for demonstrating procedures which involve sonoelastography. The prostate, along with structures simulating the rectal wall, seminal vesicles and urethra, is contained within an 11.5 x 7.0 x 9.5 cm clear plastic container. A 5 mm thick simulated perineal membrane enables various probes and surgical tools to be inserted into the prostate. Based on the popular CIRS Tissue Equivalent Ultrasound Prostate phantom. The Model 066 contains 3 isoechoic lesions that are at least two times stiffer than the simulated prostate tissue. Under normal ultrasound they cannot be detected but are readily visible on elastograms.