ZEBRA's check set specialized for memorization, including red, white, and green check pens. - Brand: ZEBRA - Product Name: Check Set - Set Contents: Red check pen, white check pen, green sheet - Purpose: Memorization aid tool - Features: Design specialized for memory retention My child purchased this when they were a student. The item is approximately 5-6 years old, so there is some deterioration of the packaging. They said they opened it once and tried it on the back (see image 5). They haven't used it since, so we haven't confirmed if the ink still works. Please consider this before purchasing. ⚠️Please understand that this item has been stored at home for a long time by a non-professional. If there are any oversights or omissions, I apologize. Thank you for looking! Listed on R7.10.15