231P = 2-3-1 Put: he buys 2 puts of the lowest strike, sells 3 puts of the center strike and buys 1 put of the upper strike. See it as 2 credit spreads + 1 debit spread combined, with the same short leg.
In this case, I expect, he bought 2x 3105 Put, sold 3x 3120 Put and bought 1x 3135 Put...