36-48v controller is on backorder until ~July 1st.
This is a very compact brushless system using a sealed Motenergy motor and Curtis controller good for either:
175 amps peak at 72 or 96v
350 amps peak at 36 or 48v
Tyco sealed Contactor
Real world data shows the ME1718 will spin approximately 4200 rpm with 48v when using this Curtis controller.