After having seen this section of B&B got me to remembering that squirreled away somewhere I have a pipe that has been dormant for some 40 years. So I dug it out. It has no name on it, but, on unscrewing the stem there is a small tube with a little perforated ball on the end that slips in near the bowl. What kind of pipe is this? Is this type of pipe desirable/undesirable? Oh, and before you ask, my picture taking/posting skills are almost zero.