what is the meaning of the second argument?

[planewave]

in the demo

crcb.search([[165,  16,  2,  7,  85,  163,  209,  114,  21,  131,  143,  144,  52,  187,  183,  142,  180,  39,  169,  76],
            [165,  16,  2,  7,  140,  39,  242,  202,  181,  209,  220,  248,  156,  112,  66,  128,  236,  187,  35,  176],
            [165,  16,  2,  7,  113,  105,  30,  118,  164,  96,  43,  198,  84,  170,  123,  76,  107,  225,  133,  194]],
            
           [[253,  14],
            [90,  38],
            [248,  236]]
)

I know the first three lines are the sample msg, but what is the meaning of these arrays?

           [[253,  14],
            [90,  38],
            [248,  236]]

and where can I define the CRC length? for example, with CRC RevEng, I can type something like

./reveng -w 16 -s 282FAC4DD9 2B6BACD581 2F2AAC37BC AF2EACC022

to search for the CRC-16

thanks in advance