Review on 🪑 Mophorn Swivel Chair Base 28 Inch, Heavy-Duty Office Chair Replacement Base - Supports up to 320 lbs, Office Chair Base with 5 Inch Stroke Length, Replacement Chair Base Featuring Bottom Plate Base Cylinder and 5 Casters by Wendy Mellgren

In short, after the return date passed, the chairlift cylinder failed and stuck in the lowest position, I needed the top one. So it's not strong or comfortable, and as you say it requires heavy build conditions that caused the chair to tip forward unevenly, making it very uncomfortable to sit on the floor for more than 20 minutes or so without constantly to have to readjust. I feel cheated and wasted $70 of my hard earned money on this purchase. Although the wheels are holding up well I would not recommend anyone to buy a replacement from this brand. Such a shame! VL