does the body of the tube have a rectangular 'spot' anywhere on it?
something that looks like there may have been a cloth sticker on it at some time?
... there are lots of rumors about the red tip tubes; dunno if any of them are true... medical useage is one of them (more reliable)
something that looks like there may have been a cloth sticker on it at some time?
... there are lots of rumors about the red tip tubes; dunno if any of them are true... medical useage is one of them (more reliable)