These are three-point internal micrometers that offer you the following benefits: 

• Individual micrometer.
• Titanium-coated measuring pins give you excellent durability and impact resistance.
• They also have excellent resistance against water and dust (IP65 protection level), allowing you to use this product in machining situations that include splashing coolant fluid.
• Large LCD display with character height of 7,5 mm enables you to read measurements easily.
• Without setting rings or extensions.