Edmund, those are had to find nowadays with all the instant-read digitals models out there. But what fun is that? I found one in a local store that sells nautical instruments recently that I'm very excited about, pun intended. It's a professional glass instrument made by Taylor, model #21421. It is similar to the old-fashioned glass rectal thermometers except that it is longer (it's six inches long) and fatter. It is triangular shaped for the prismatic effect, and has a permanent cap on the end which prevents it from getting lost where it shouldn't. The whole thing goes into a slick plasic case which has a clip on it for pocket readiness. Check The Taylor Instruments website, www.taylorusa.com. Look under industrial products, then under "speciality devices." They have a few different models listed, some that have to be shaken down, and some that don't. Some of them register up to 200 degrees for really "hot" patients. These cost in the $10-15 range, but are accurate and excellent quality. Good luck, and a salute to beautiful bottoms everywhere!