The invention includes a main body which is composed of an annular vertical surface, a top surface, a side annular surface and a bottom surface. The annular vertical surface formed with screw parts thereon is connected to the side annular surface with the top surface. A concaved containing region is annularly formed between the side annular surface and the bottom surface. A throughout-like communication part is formed on the bottom surface.本發明包括有一本體,其至少可分為環立面、頂面、側環面及底面所組成,其中,環立面上形成有螺紋部,且環立面係藉由頂面而連結至側環面上;又,側環面及底面間可環繞圍成一凹陷狀容置區域,且底面上形成有一貫穿狀的導通部。2...本體20...環立面201...螺紋部205...止滑扳動部21...頂面22...側環面23...底面24...容置區域25...導通部251...螺紋255...限位部
