Oakton 6mm Single-Junction Epoxy Body Small-Diameter pH Electrode, Standard, 0 - 12 pH Range Single-junction electrode for general-purpose applications Epoxy body for impact resistance and durability Small (6 mm) diameter for measurement in test tubes Standard electrode for a wide variety of applications Bayonet Neill-Concelman (BNC)-connected combination reference and measuring cell, for ease of use and to provide tight coaxial cable connections