VEVOR Murphy Mounting Wall Springs Mechanism Heavy Duty Support Hardware DIY Kit for King Queen Bed (Vertical), White

Well that's really subjective. It helps you lift. So it's not so "much how much can it hold", but "how much does it help you lift?". My bed is like 300 pounds, but it feels like 50 pounds.

Don't waste your money unless you want to figure out how to build the bed without instructions. The one I purchased nearly a year ago is still in the box. If you want to go for it, it should handle most mattresses. The weight the bed can handle with someone on it when open depends on materials and how sturdy you build it. I gave up and bought the more expensive kit and it's less of a headache.

I use these with all 5 springs installed to handle a very dense queen-aide memory foam mattress, and a wooden bed frame made with 5/4” x 4” poplar boards and “faced” with cabinetry. So it’s a fair bit of weight that the springs handle well. I’ll add a short video that shows the bed opening, and you can find more details on YouTube

Its more dependent on the bed structure and the bed size not the hardware

I build them professionally, and for that much weight, I would use an hydraulic system like Rockler! Mine is pretty light weight with a 4” Ikea mattress mounted on the door!

About the Mounting Wall Springs, it's 11.5kg

My frame and mattress combined are less than 100 pounds and it works just fine. I don't know how this product will work for you but the specifications in the ad say the maximum bearing weight is 992 pounds (450 kg). Hope that helps.