2 Manufacturers - China ones good; Vietnam ones BAD.
China model: Sturdy with springs and very comfortable. Highly recommend ones from CHINA.
Vietnam made ones have wood bottom, no velcro cover hiding the bottom, stiff and not as comfortable. Have tried to resolve with without any luck so after 3 replacements, assembled one set.
Beware
2 Manufacturers - China ones good; Vietnam ones BAD.
China model: Sturdy with springs and very comfortable. Highly recommend ones from CHINA. Vietnam made ones have wood bottom, no velcro cover hiding the bottom, stiff and not as comfortable. Have tried to resolve with without any luck so after 3 replacements, assembled one set. Beware