The Castroviejo Needle Holder (18 cm straight, 7 inches) with lock and tungsten carbide (TC) gold coating is a specialized surgical instrument used in various delicate procedures, such as ophthalmic surgery and microsurgery. Here's a breakdown of its features:

• Length: 18 cm (7 inches) – This is the standard size used for precision tasks, offering good control and maneuverability in delicate surgical areas.
• Straight Design: The straight configuration provides better accessibility in certain surgical settings.
• Lock Mechanism: The lock keeps the needle holder securely closed, ensuring that the needle or suture is firmly grasped during procedures.
• Tungsten Carbide (TC) Gold Coating: The TC coating enhances durability and provides a superior grip on needles, making it ideal for handling fine sutures. It also improves the instrument's longevity and sharpness retention.
• Material: Typically made of high-grade stainless steel with the TC gold coating for enhanced strength and resistance to wear.
• Applications: This needle holder is often used in eye surgeries, microsurgery, and other fine suturing tasks.

The TC gold coating offers the advantage of longer-lasting sharpness, reduced wear on the jaws, and enhanced handling of delicate surgical needles, making it a popular choice in precision surgeries.