Fluke FTPL-1 Fused Test Probe Set with Test Lead, -20 to 50 Degree C Operating Temperature SureGrip fused test probe and test lead set with built-in replaceable fuses for additional measurement protection The probe fuse does blow, these fused test probes will still allow the meter to indicate live voltage, helping to prevent a possible misreading of no voltage present 2mm threaded probe tips include removable 4mm spring contacts and removable insulated caps for probing closely spaced leads CAT III 1000 V, CAT IV 600 V, 10 A rating -20 to 50 degree C operating temperature