Airplane seat-back phone- and tablet holder

Made this to watch movies on my phone during flights. Works at least on WestJet 737 and Q400 planes, in economy and business class seats, even if seat in front is reclined. Probably fits most plane seats that have the little extra pocket for the safety briefing cards, idk. Print two of them to hold your phone.

The through-hole is 4mm, and can be used with a long bolt or a 3d printed pin, to hold the two pieces, see photos. Its not really necessary though.