Hi SteveHi Gary,
Probably about 100 years ago the splice joint was invented, two sections of a rod are sliced at an angle and the 2 sections fit together and are bound together - in the early days this was wet leather these days it's normally clear hockey tape.
The joint has made a revival in the past 20 years or so, since it makes for a bamboo rod with more of a one piece feel.
When the rod is broken down, the ends become susceptible to damage due to the very fine slim tips. A splice protector fits up against the splice with the thick end of the protector against the slim tapered tip and bound to it with a cord attached to the protector.
thanks for the explanation also watched the Bob Clay video very interesting (we never stop learning)