GS40A-4IN1 aims to be your 6s dream ESC.
To achieve that goal, Spedix uses the lowest RDS standard size 5x6mm MOSFET with only 0.85mOhm resistance, making the ESC 40A capable in the real world. In contrast to the 30V MOSFET used by most competitors in the market, this 40V MOSFET improves the overall reliability in fast response to throttle signals. To meet the strict requirements in racing competition, Spedix designed a 50V power supply circuit and 5V clean output. To improve high current workload, Spedix uses high TG PCB of 6 layers even though the cost is much higher. The included heatsink doesn't add to the size of the ESC and is only covering the parts that count, reducing weight compared to a full board heatsink.
On top of all these top quality features, Spedix engineers managed to control the dimensions to be the same as a standard 36mm flight controller board, without sacrificing the precious space in a quad.