This Nikola Tesla collectible pen is engraved with one of Tesla's most famous inspirational quotes, "To find the secrets of the universe, think in terms of energy, frequency, & vibration." This durable, heavyweight pen is a worthy addition to any pen collection, and makes a suitable gift for scientists, inventors, engineers, students, professors, and Tesla fans! It weighs 46 grams and measures approximately 5.6 inches long. The replaceable ink cartridge offers an alternative to disposable ballpoint pens. This pen fits the standard G2 ballpoint pen refills, also known as Parker-type refills.