This is a new quick release block for use in the EFT E series.
 This is a part that allows you to easily and simply detach the spray can from the EFT E series airframe and replace it with a spray can.
 You can simply install it in place of the existing landing gear mount, and since it opens inward, you can install it without opening the landing skid.
 To prevent the skid from falling down due to its weight after installation, there are fixing bolt holes, and since they match the existing landing skid bolt locations, installing the landing skid and fixing it with bolts will prevent the skid from falling off.
 (Even if you don't install additional fixing bolts, the landing skid won't come off easily if you just lock the locking bolts properly.)