A track joiner allows the wheels on your hardware straps to smoothly pass over the junction point of the two tracks. This can also create a cleaner look in that the track will appear more like one larger track. If you want your doors to stop in the middle when the doors are closed, be sure to include the inner door stops. If you want your doors to stay firmly closed, we recommend using our Easy Clip Soft Close attachment which will ensure that the doors remain completely closed. This eliminates any banging of the doors or opening as a result of the track not be mounted perfectly square. It also ensures your doors can be easily opened and remain in the full open position.