P14 Sentek pH Electrode-Combining ergonomic practicality with unrivalled performance, these electrodes also feature: Extremely fast response .Virtually unbreakable construction. Exceptionally stable reference system .Snap action closure for easy refilling and zero leakage. High quality ABS cap with unique ‘soft grip’ Rugged ‘long life’ pH glass membrane .Electrode P11. Glass bodied, refillable, general purpose combination pH electrode. Recommended sample types: brewing, blood products, cement, cosmetics, dairy products, education and low ionic solutions. Electrode P14 & P17. Epoxy bodied, gel filled, general purpose combination pH electrode. Recommended sample types: brewing, cosmetics, education and field use.