var nonLinearStepSlider = document.getElementById('slider-non-linear-step');

noUiSlider.create(nonLinearStepSlider, {
    start: [500, 4000],
    range: {
        'min': [0],
        '10%': [500, 500],
        '50%': [4000, 1000],
        'max': [10000]
    }
});