Hammerhead Service-21 SERVICE-21 Pool Vacuum Cleaning Machine with 21" Head and 40' Cord. Service-21 and Service-30 units are meant for pool-to-pool route work, and include a mount assembly for transport. Mount assemblies (HH1306) are compatible with any 2" hitch receiver (vehicle hitch not included). The two standard units are the Service-21, which has a 21" vacuum head and a 40ft power cord, and the Service-30, which has a 30" vacuum head and a 60ft power cord. Service-21 units are also available with a 60ft power cord as an option. Service units ship partially assembled. Some assembly and set-up of the vehicle mount is required.