Buffer, Reference Standard, pH 4.00 ± 0.01 at 25°C (Color Coded Yellow) 1L
pH made Easy. Everything you need and want in a pH Buffer. NIST Traceability. Consistent, reliable performance. The tightest specification (+/- 0.01 pH unit) on all buffers. Long Expiration dates. Temperature conversion charts for all Buffers up to pH 11. Multiple sizes to fit your usage and budget constraints. All combined in one of the most comprehensive pH Buffer line available.