These probe clips feature a spring loaded wire hooked probe which retracts into the probe moulding. The probe material is copper & the housing is ABS. Probes are available separately in red or black. Specifications Length 54.5mm Cap diameter 10.5mm Cap stroke 3.5mm Probe tip 4.3 x 2.5mm Wire entry hole 3mm Probe length 4.4mm Contact resistance 10m Omega Insulation resistance 10 M Omega Withstand voltage D150 V Current rating D150V0.5 A Operating temperature-30deg C to 60deg C