Stool
In sailing boats the stool is the piece that together with the cross or cross, serves to join a male club and a mastellero or two mastelleros each other. In wooden ships the stool was of the same material and of rectangular shape, with two holes, one generally square that fitted to the spike of the calcés of the stick or mastellero and the other, round, to the bow of the previous one, where passes the mastic cook or mastelerillo, whose wick fits in the corresponding hole of the cross or crosshead. In metal sticks the stool is reduced to a double iron or steel zigzag, fixed one to the pole and the other to the mastellero.
wiki