Model: 9dBi Dual-Band DirectionalLong Range Wireless Coverage, Increase the Strength of Dual-Band Wi-Fi Devices up to 350 percent. The HD9DP Hi-Gain Dual-Band 9dBi Directional Antenna Kit is an antenna for extending the range of your 802.11 a/b/g/n Wi-Fi devices. The HD9DP increases the wireless strength from a standard 2dBi (decibels) to a staggering 9dBi, resulting in up to 350 percent increase in the wireless coverage and strength.