If you read the announcement it will spell it out. The offer will be (approx) $10 per IIN share plus synergy benefits of $1.37 per share.
This is a lot better than the TPG offer, and I'm not surprised that another offer has come along.
Interestingly MTU disclose in their announcement that the deal will be EPS accretive to them in the first year in the "mid to high single digits". So this is still a relatively inexpensive deal and there could be room for someone to go over the top of MTU or for TPG to come back.
IIN Price at posting:
$8.66 Sentiment: Buy Disclosure: Held