The garden dibber, or garden dibble as others would call it, is essentially made of two basic parts: the dibble head and the dibble handle. The dibble head is molded concrete. The dibble handle is really nothing more than a metal rod that sticks out from the dibble head. It's a scrap reinforcement bar (or rebar) that is only 9 mm thick.
The rebar, as I've found, is really too thin for my hand to hold. The dibble head, being made of concrete, is a bit heavy and there isn't enough leverage when holding the garden dibble.