My version is just a large plastic bag, some gaffa tape, and a piece of bicycle inner tube. The mat inflates in a fraction of the time it takes doing it by mouth (2 and a bit bags of air), you don't get dizzy
, and you avoid condensation inside the mat. Weighs 30g and takes up barely a sliver of space (slips into the mat's stuff sack with the mat). The only remotely challenging part is cutting the hole the right size- big enough that you can slip it over the outer part of the valve easily, but small enough that it forms a tight seal on the threads of the valve. I'm not sure how durable the plastic will be- I think it should last a while as long as I don't apply excessive pressure when inflating. If not I'll just try a heavier garbage bag or something.- Outside
