This spacer is designed for the ZMR250 and holds mini 20A esc's. 10mm standoffs make This build have a total height of 16mm.
This design provides a clean and thin build whilst still allowing for good airflow to the esc's. The hole allows easy usb access to the Naze 32 or similar Flight Controller.
The part was designed for the LittleBee 20A however i believe it would be suitable for other esc's that are similar dimensions (eg. Kiss 18A, BearHug ESC, BL20A or SN20A )
Note: If printing in PLA be very careful when applying heat shrink, the temp required is close to PLA melting point.