Has anyone tried lumber support mesh for chair

[suds]

I came across lumber support mesh online. It seems nice has anyone tried those? Are they comfortable to use on normal chair


http://www.ebay.in/itm/Car-Seat-Cha...7?pt=LH_DefaultDomain_203&hash=item33a291ef55

http://www.ebay.in/itm/New-Comforta...5?pt=LH_DefaultDomain_203&hash=item20fad4d805

http://www.amazon.in/Massage-Suppor...6774&sr=8-1-spell&keywords=lumber+support+net