Description: As probes, they are used for the drilling of the insulation of wires to allow for automotive electrical measurements without causing damage to the wires. They can be used as a pin probe of the to work with small circuit boards. The set of 15 probes also comes with 30 pins of replacement; there is no need to replace the entire probe. Its small diameter, extra pin makes it great for the perforation of the insulation on wires. It can connect with 4mm banana plug as the following picture show. Specification: Probes color: Black/ Blue/ Yellow/ Red/ Green The probes: 15 pieces The needles of the replacement: 30 pieces Full length of the probe (1 piece): 65mm/ 2.56inch The length of the pin: 37mm/1.45inch Package Includes: 15 Pieces Probes and 30 Pieces Replacement Needles Note: Color maybe slightly different due to different monitor. The above size is measured by hand, please allow slightly difference. Thanks !