This dual n-channel MOSFET board can sit flat on top of a standard Keystone dual 18650 battery sled. It measures 31mm by 15mm. It's designed for 2S input and it's recommended maximum current limit is 50 amps. Select 10k or 100k ohm potentiometer, voltmeter and fire button. You can purchase this PCB populated (i.e. with the components) or unpopulated. Delivery of populated boards may take longer than normal.