This large "headpins" are shells and stones set in prongs with a long paddle on top flattened and with a perforation. Made to be interlocked, used all at once or as a shell focal companion, the paddle on top can be cut to form a loop and make shorter pendants as well.
They measure approx. -measuring Just the shell/stone area 36 x 28mm, 29 x 26mm, 25 x 25mm, 22 x 30mm, 20 x 23mm.