Oakton pH Calibration Buffer Pouches, pH 4.01, 20/pk

Buffers are traceable and offer ±0.01 accuracy at 77 °F (25 °C). Pack of 20 pouches.

• Single-use pouch—just tear, dip, calibrate
• Available in common pH values 4, 7, and 10
• Standardized to NIST-traceable pH references
• 1 year warranty