| 摘要 |
<p>The unit comprises two identical shells of an appropriate size made of a rigid synthetic material. The shells are provided with hook elements to be engaged with complementary openings at the opposite shell. A large curved recess is positioned at the upper edge of the parts for the insertion of a central connecting element. The element is produced by dual component injection molding with a more rigid inner area and a softer edge both connected by a toothed segment. The central element is secured to the shells by engaging two arms exceeding from the element with matching recesses at the shells.</p> |
