The X-21 5.8 is TrueRC's highest-gain 5.8GHz panel antenna — an expanded X-RAY design engineered for maximum main-lobe efficiency with very low side lobes and excellent front-to-back ratio. The single-feed panel format delivers over 21 dBic at 5.8GHz across the 4.8–6.3GHz band. Suitable for UAV command and control, long-range wireless networks, and research or defense communications.

This is a VERY High gain antenna, Use for Long range flight ONLY. 

Specifications

• Frequency: 4.8–6.3GHz
• Gain @5.8GHz: 21 dBic
• Gain @5GHz: 16 dBic
• Polarization: RHCP
• Beam-width @-3dB: 15°
• Connector: SMA
• Dimensions: 252.7mm dia. × 26.5mm
• Weight: 255g
• Mounting: 1/4-20 mounting point