Yes, the pigtail is always necessary for outdoor deployments because you need lightning protection. The 3765/67e come with 6 reverse SMA connectors on the AP. The lightning protectors are using reverse N connectors, as well as the LMR cables and antennas. The pigtail converts the R-SMA from the AP to R-N to connect to the LP. Please note that if you have any unused R-SMA connectors on the AP, they should be terminated with a R-SMA terminator to prevent RF leakage.