The fountain pen P105 has a replaceable ink sac

Hero P105 Fountain Pen Student Practice Pen Business Office Replaceable Ink Capsule Signature Fountain Pen
▸ Product Model: P105 Fountain Pen
▸ Ink Supply System: Replaceable Ink Capsule Design
▸ Nib Type: Standard Iridium Nib
▸ Adaptation Specifications: International General Ink Capsule
▸ Product Net Weight: 25g±2g