Another choice might be:http://www.lindelectronics.com/cgi-b...detail_product
From lindelectronics. They are pricey, but very tough and reliable. My husband used one for his Toshiba laptop (in a work truck) and was very happy with it. They did not used to have one for the m6805, but do now. (Should also work for the m6810.)
Notice though that: "This adapter can not be used in the airline in-seat power systems and it is not provided with the special connection cable. The air in-seat power systems are limited to an output of only 75 Watts."
This makes me wonder if any
adapter would work with in-seat power plugs.