The R2990 is a simple black K-Type adapter that converts a standard mini-connector thermocouple probe into dual shrouded banana-plug inputs, letting it plug into REED multimeters and clamp meters equipped with contact-temperature measurement. It has no sensor of its own -- accuracy and range depend entirely on whichever Type K probe is attached to it. It's a low-cost way to extend an existing meter's compatibility with REED's broader probe lineup.