Alt Intv switch

Hello,
Does anybody know what is the role of the Alt Intv switch of the 737PMDG ?

Another question, Can we push the Altitude Selector in the real 737NG (like Airbus) ?
Thanks.
Does anybody know what is the role of the Alt Intv switch of the 737PMDG ?
Another question, Can we push the Altitude Selector in the real 737NG (like Airbus) ?
Thanks.