Peaceful bubble harmonics, instead of the desperate sound of sucking for air. Let's face it, the v4 topcap boasts the worst, most restricted airflow ever: it actually aggravated my wisdom tooth all that vacuum. Bypass all that with this useful water tool. I like how I can use it leaning back, other ones I have I must hunch forward over the mod. I have not noticed any flaws in mine yet. Great price.