Two PINS, cap, fore-end that fit across the fore-end and mate up (? if you're VERY lucky that is.....) with the corresponding holes each side of the CAP, fore-end. They have little stepped flats on either end and these flats face inwards - to face each other. The BAND, upper sits across the flats and it is the band that holds the pins in place if they are loose. Clever eh!
These pins are also the same diameter as the 4BA screws and also the pin, axis trigger and sear and backsight axis pin. All done for simplification