Hi, bought an ottoman base with 800N gas struts which from day one l've struggled to lift. Retailer have sent out an assessor from FIRA, who has concluded the struts are not stronger enough to lift my old mattress which weighs around 40kg. I've tried it on another ottoman with 500N and lifting is easy! I don't to change the original spec and have asked for a refund as base does not do what it's supposed to. I would like to buy another ottoman but would I run into the same difficulty as I cannot give the precise of weight of my mattress because it's no longer made. I have emailed the manufacturer who said it would be around 40kg. I see your ottomans are fitted 70N. Is this a typo?