CT3978B Cal Test Probe NewFeatures: Probe bodies with 4 mm sheathed banana jack connections UL 61010 031 rated Accessories "snap lock" to probe bodies Cap on probe tip provides CAT III CAT IV usage Pair of DMM probe bodies with 2 mm (. 080) diameter x 19 mm (0. 75) probe tips for all test applications. With locking cap installed, the probe meets 600 V CAT IV applications. Remove the safety cap for access to the standard 2mm tip and to attach tip accessories.