Pen for writing on screen of computer, has rounded tip, housed and retained inside coaxial cavity provided at one end of stem, which is made of monocrystalline synthetic ruby or sapphire and ceramic materials
摘要
<p>The pen (1) has an elongated stem (2) provided at one end (2e) with a coaxial cavity (3) inside which a rounded tip (4) is housed and retained. The tip is made of monocrystalline synthetic ruby or sapphire and ceramic materials.</p>
