This is the oil filler plug for the Honda CVT transmissions on Civics 2014 up CVT and many other Honda listed below.

You need to install an O-Ring in the Lower groove. The Upper groove is simply to place your fingers for grip when removing the plug.

Honda Part No. Cap, Filler (Atf) (A)(Cvt) - Honda (25615-5T0-004)

2020 Honda Civic LX, Sport 1.5L L4 - Gas, 2.0L L4 - Gas
2020 Honda Fit EX, EX-L, LX, Sport 1.5L L4 - Gas
2020 Honda HR-V EX, EX-L, LX, Sport 1.8L L4 - Gas
2019 Honda Civic LX, Sport 1.5L L4 - Gas, 2.0L L4 - Gas
2019 Honda Fit EX, EX-L, LX, Sport 1.5L L4 - Gas
2018 Honda Civic EX, LX 1.5L L4 - Gas, 2.0L L4 - Gas
2018 Honda Fit EX, EX-L, LX, Sport 1.5L L4 - Gas
2018 Honda HR-V EX, EX-L, LX 1.8L L4 - Gas
2017 Honda Civic EX, LX 1.5L L4 - Gas, 2.0L L4 - Gas
2017 Honda Fit EX, EX-L, LX 1.5L L4 - Gas
2017 Honda HR-V EX, EX-L, LX 1.8L L4 - Gas
2016 Honda Civic EX, LX 2.0L L4 - Gas
2016 Honda Fit EX, EX-L, LX 1.5L L4 - Gas
2016 Honda HR-V EX, EX-L, LX 1.8L L4 - Gas
2015 Honda Civic EX, EX-L, HF, LX, SE 1.8L L4 - Gas
2015 Honda Fit EX, EX-L, LX 1.5L L4 - Gas
2014 Honda Civic EX, EX-L, HF, LX 1.8L L4 - Gas