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 ]
	}
});