Wide compatibility and precise matching: This product is designed specifically for the F4019-2 model and is perfectly compatible with mainstream brushless motor models such as 1503, 1505, etc. (compatible with 4 pairs). Please double check your machine model before purchasing to ensure that everything is foolproof. Complete installation, worry free and convenient: The kit already includes installation adapters and screws, so you don't need to purchase any additional parts. Ready to pack, easy and simple, making your maintenance work more convenient than ever before.