Our self inking stampers come in 2 sizes 2.36 X 1.57 (A) and 3.00 X 1.50 (B). You can determine which size stamper you have by the first letter in your item number or the stamp size shown on the stamp design page. For example, the Item Number for The Abigail Stamp is (B-Abigail) and the size is showing as 3.00 X 1.50 which would use a (B) size ink cartridge.
This black ink cartridge is designed to fit in our (A) style stamper which measures 2.36 X 1.57. If your stamp design starts with the letter A then you can use any of the (A) ink cartridges.