Heavy-duty steel base for improved strength and durability. Sanitary tray with built-in measuring tape provides safety, reads up to 23" x 1/4" or 58 cm x 1 cm (1522KL). Child seat provides safety and comfort and reduces infant movement (1524KL). Sanitary tray and child seat made from easy-to-clean ABS plastic. Rotating poise bars lock-in for error free operation. Factory calibrated to ensure accuracy.