A query came up on another URB board I moderate: http://pub41.ezboard.com/fthedudepitfrm37 "I asked this over at Thomasik but they're puzzled too! Can you help?......OK, this may qualify as a silly question but.... I use Weichs and every set I bought has a small piece of tubing slipped over the D string. I've asked just about everyone (including the UK distributor) what the purpose of this mystery component is but no-one seems to know. I've tried using it at the string/bridge contact point which seems the only logical application but all it did was to cut the sustain. There has to be a reason for it to be supplied...but what? Your answer eagerly awaited!! " I remember using the tubing on violin E and A strings sometimes, which cut down on the harshness a bit, but a bass D?? Anyone??