Somehow, I have acquired 3 stainless(?) steel units over the years.
1. Stanley Aladdin brand 37cm x 10cm. 1200g. screw cup and cork. 1,000ml capacity.
2. Thermos brand 30cm x 9cm. 900g. screw cup and cork. 1,000ml capacity.
3. No-Name no-brand 28cm x 6cm. 500g. screw cup and very good threaded flip cap. 425ml capacity.
It's 90 miles east to a town and 140 miles west to the city. In between is rock, water and forest.
Nobody lives there. No coffee shops. Bring your own!
#1 and #2 are hopeless fights in the moving vehicle. Not used once a year.
#3 is very convenient, even to pour coffee on the move. Every few weeks.
The flip cap stopper on #3 has remained water tight for years,
no matter how many times I have dropped that thing on its head.