The two-suiter overcalls after an opening of 1 of a suit are the famous Michaels.
A two-suiter overcall guarantees:
- two strong suits of at least 5 cards,
- about 10HCP, (sometimes less......with no top limit),
- the high cards in these 2 suits.
- You should pay more attention to the quality of the suits and to the vulnerability than to the number of points !