Hello, the rope of this product has five thickness specifications, the rope thickness are 1MM (button thickness 2MM), 1.5MM (button thickness 2.5MM), 2MM (button thickness 3MM), 2.5MM (button thickness 3.5MM), 3MM (button thickness 4MM). Because the button is always 1MM thicker than the rope, so you must pay attention when choosing the rope. For example, if you choose the 2MM specification, the pendant hole must be larger than 3MM to wear it in. You must pay attention to this.