This listing is for a matched pair of On Semi ( previously Fairchild before acquisition by On Semi in 2016) FQA36P15 MOSFET. They are widely used in DIY of class A power amplifier output stage. This part is already obsoleted so is a hard-to-find part.
The pair are Vgs matched to 100mV tolerance or better.
We use our in-house designed fixture for the matching. The circuit is as the picture below with drain current running at 1A or higher and use Agilent( now Keysight) 34401A six and a half digit multimeter to do accurate and fast response measurement.
This is our always method for matching of power mosfets.
Those using simplistic transistor tester ( such as MK-328 transistor tester) cannot give the right results. The 006P 9V battery in the transistor tester is unable to give enough current even to turn on the MOSFETs !