The ESC is HobbyWing/Backfire customized program ESC which best fit Backfire electric skateboards. Since June 2020, Backfire updated ESC enclosure for the product lines on hand now. The ESC enclosure still fits the original deck and matches the screw holes but with some major differences：

New esc enclosure works with a smaller power button than the old enclosure.
New esc enclosure has a bigger heat sink plate
New esc enclosure has rubber seals and back cover.
New esc enclosure has two holes for the cable to connect with the motor cables, and works with the 9 pin cables perfectly. But if you want to use the new esc enclosure with your old esc and motor cables with MR30 plugs, you have to modify it or remove the rubber seal on the back holes to get the wires through.
With the new esc enclosure and 9 pin cables, you could plug and unplug the esc and motors without take off the esc from the deck. While with the old esc enclosure and old style motor wires with MR30 connector, you have to take off the esc enclosure from the deck before you can connect or disconnect the wires between esc and motors.

Disclaimer:

Each option is special program to fit the specific model, please pay attention before placing the order.
Might NOT compatible with other brands due to different programs.
MR30 connector motors will not work with the new style ESC with the 9 pin connector. People who got their boards before June 2020 all have the MR30 connectors. While people who bought their boards after June 2020 will mostly have the 9 pin connectors. Please verify before purchase.
The XT60 connector to the board & battery remains the same.

Backfire ESC