Clear transport/calibration cup that fits over the sensor guard to hold calibration solution during calibration, and doubles as protection for the probe end during transport.

Used with: YSI 556 (per price list); note YSI's own spec page lists this cup against its EC30A/ORP15A/pH10A/XLM/600XL handheld line rather than the 5200A noted on the internal price list — worth double-checking against the actual cable/probe you're pairing it with.

556 Manual