Thermal paper Prescription rolls - Core: 1" - Roll Width: 4 3/8" - 250" roll (approximately 500 scripts/roll) - black mark sensor on back of sheet - Approved for Controlled Substances Prescription - 16 rolls/case - Security features includes: Unique Security Background/Production Batch Number/Hidden Message Technology/Reverse Rx/Artificial Watermark - Works with Star TSP800/TSP800Rx/Citizen CLP521/CLP7200/CTS4000/Datamax E Series/Dymo 4XL