The one I got is:

https://www.amazon.com/3D-Printers-4-Sheets-Available-Thicknesses/dp/B07GRSGQN6/ref=pd_bap_rp_12?_encoding=UTF8&psc=1&refRID=KXCM63Q6GGXB54WBX19Z

200 micron specifically, though I'm not too sure on the pros and cons of different sizes. I haven't heard anything real specific/noteworthy, so I went with the thicker hoping it would be tougher.

An alternative is the Epax Non-fep which is supposed to have lower adhesion, but it's a fair bit more expensive and I think I heard somewhere that it was a bit weaker:

https://www.amazon.com/EPAX-Thickness-Printer-Wanhao-Photon/dp/B07N7TVWZJ/ref=sr_1_1?crid=3D74BLJAGQYUP&keywords=non-fep+film&qid=1575335605&sprefix=non-fep%2Caps%2C157&sr=8-1