The Micro T-1 & G33 is desribed in the game as:

A red dot sight plus scope. Toggle the scope while aiming.

This is located in southern Koani province, in the middle of nowhere, guarded by four cartel. Very easy to take out. The accessory case is inside a derelict rebel building on the side of a hill.

There’s an APC not too far away to the north-west which I already had, which is overkill for taking these guys out. You’ll have to kick in the door to access the building.

This scope for SMGs and ARs is handy to have for switching between 1.0x and 3.0x zoom levels for near and far targets, but at the sacrifice of some visibility. I prefer a red dot “Panoramic sight” for accuracy at close range on an SMG (which you’ll find in Itacua) or a PK-AS for accuracy at longer ranges on an AR (also in Itacua).