Double of 1N shows a one-suited hand. Brozel's partner may pass for penalties, but usually he will bid 2, an artificial waiting bid.
After partner's 2 bid, the Brozel bidder can pass if Clubs is his suit; otherwise, he bids his suit.
The Brozel double of 1N can be made in the direct seat or in the pass-out seat, as well as after the partner of the 1N bidder has made a weak one-suited response such as 2 or 2.
2 shows Hearts and Clubs.
What length are the suits in a "two-suited hand"? Good question. Most sources don't say. Of those that do say, most say at least 4-4; others say at least 5-4. We think of two-suited as 5-5 or more, but no sources specify that, so we just use 4-4 in BidBase..
With a strong hand and 3 suits, jump to 3 of the short suit. For example, with AKxx-x-KQxx-QJxx, over 1N, jump to 3.
If the 1N bidder's partner has made a weak one-suited bid, 2N shows the other three suits. A cue bid shows the other three suits and a stronger hand.