Connecting Leads Blue - 300mm, 4 mm stackable plug both ends -EIS-PH1055V offers a thoughtfully designed, durable resource for hands-on learning. Connecting Leads with 4 mm stackable plug at both ends. Connecting Leads with 4 mm stackable plug at both ends. The plugs have nickel plated split hollow pins and are connected by high quality flexible wire. Length 300 mm, Blue.