Spigots are a short strong price of paddle shaft small enough to fit inside a paddle shaft, to repair a break or more commonly to make a 1 pc paddle into a 2, 3, or even 4 pc paddle for easy of storage and transport.
The pins can be purchased separately, as can shafts to suit. 

These spigots are 16cm Long.

Outer dimension: 26.7mm
Inner Dimension: 23.9mm
(may be minor variation)

Vernier Callipers are the only effective way to accurately measure your shafts internal Diameter (ID).

For repairs, you can get away with a slightly small joiner approx 0.5mm smaller, but for a 2pc it really should match perfectly, so it slides together without resistance, but then has minimal play.

The Kit:

1x Spigot (Connector / adjustment tube)
2x Pins 
1x Spring (pins & spring are shipped in a bag found inside the tube)

Instead of using the piuns & spring (and drilling a hole in your paddleshaft), you can us Kajak Sport Ferrule: 214038, 214046 (or older codes 211416, 211616, 211816)

The Outer Diameter is the tube measurement that needs to fit inside the ferrule and inside the body of the paddle shaft.
When measuring your paddle shaft the inside measurement of the paddle shaft should be slightly more than the outer diameter of the connector tube.

Recommended Adhesive:  Bostik Treme Clearfix (transparent) for composite shafts