Specifications: The ink level is clearly visible. A cartridge for dry erase markers . Material: Cartridge: R-PP, Plug: PE; Product Size: Shaft Diameter: 0.7 inches (18 mm) x Length: 2.7 inches (69 mm); Oil Based Ink (Alcohol-based); Cartridge Replacement; Quantity: 1 piece; Pack; Body: PM-B501, B502, B503, B513; Art Supplies Dot Com Postcard A; Store Limited Product! 1 x Cute Animal Postcard