Here is the $40 Coupon for DJI Spark Remote Controller.
Coupon Code: XEYQVUZH
100pcs Limited!
Input the code before checkout.

Spark’s remote controller features a brand new Wi-Fi signal transmission system, capable of controlling the aircraft and gimbal camera at a maximum transmission range of 1.2 mi (2 km).

The remote controller can connect to a mobile device wirelessly and display a live video feed via DJI GO 4. Its folding clamps allow you to attach your mobile device securely. Maximum remote controller battery life is approximately 2.5 hours.

Specification:
Brand:  DJI
Item No.: Spark
Item Name: Remote Controller
Operating Frequencies: 2.412-2.462 GHz, 5.745-5.825 GHz
Max Transmission Distance (unobstructed, free of interference):
2.4 GHz: 1.2 mi (2 km, FCC), 0.31 mi (0.5 km, CE), 0.31 mi (0.5 km, SRRC)
5.8 GHz: 1.2 mi (2 km, FCC), 0.19 mi (0.3 km, CE), 0.75 mi (1.2 km, SRRC)
Operating Temperature Range: 32°F to 104°F (0°C to 40°C)
Built-in Battery: 2970 mAh
Transmitter Power (EIRP):
2.4 GHz: 26 dbm (FCC), 18 dBm (CE), 18 dBm (SRRC)
5.8 GHz: 28 dbm (FCC), 14 dBm (CE), 26 dBm (SRRC)
Operating Voltage: 950 mA, 3.7 V
Supported Mobile Device Size: Thickness supported: 6.5 mm-8.5 mm
Max length: 160 mm