This SkyStarsRC Fly Stack F405 HD2 3 - 6S 30x30 Stack/Combo is perfect for power - hungry professional - level pilots. The F405 flight controller and KO50 8 - bit 50A 4 - in - 1 ESC provide reliable performance. It supports 3 - 6S batteries for up to 50 amps of power. The 30x30 stack has a flight controller with dimensions of 36x36mm, weight 6g, and mounting size 30.5x30.5mm, 4mm with grommets 3mm. The KO50 50A 4in1 ESC has dimensions 41x46mm, mounting holes 30.5x30.5mm/|μ3mm, weight 13.3g and supports 3 - 6S Lipo input.