Suitable to fit Trodat Printy stamps: 4913. Comes as a multi pack of two. Replacement of the ink cartridge is made easier and cleaner thanks to special grips avoid touching the cartridge insert. The ink is water based and contains no toxic substances, no acid, no formaldehyde and no heavy metals. The ink is hygroscopic, meaning that it self regulates by absorbing the humidity of the surrounding air so that it does not dry out, allowing prolonged usage. The replacement ink cartridge are available in black, blue, red, and green.