The REED R1400-KIT pH Buffer Solution Kit includes three color-coded 16.9 fl oz (500 mL) bottles at 4.01, 7.00, and 10.00 pH, each with a viewing strip and childproof cap. Manufactured to 0.020 pH accuracy and traceable to NIST 260-53, these ready-to-use solutions are ideal for calibrating and verifying pH/ORP meters and electrodes.