M8 Hex Propeller Tightening Tool

It helps to easily tighten propeller on the motor with locknut without scratching this locknut or need to carry a wrench with you.

It works great for FlexRC Owl quadcopter: https://flexrc.com/product/owl-3-frame/
with DYS 1306 4000kv motors: https://flexrc.com/product/dys-bx1306-14-4000kv-cw/