This locking pin is a pin and cotter all in one piece. Used to hold the Upper Center Post together with the Lower Center Post. This device measures 1/4 or 5/16" diameter x 2-1/4 in. This is a square or round style shaped pin. Fits the DS9 and DL14 Sunshine Clotheslines.
Two are shown in the photos you only need one, the two types are interchangeable so either works well.