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This achievement is missable and should be done right after Mission 2, Morning Comes Too Soon.

Rather than waiting until you trigger Side Mission 04, The Calibrator, you must actually steal this item from the underground Russian casino before Koller even asks you for it. You can follow the video below for a visual guide, but what you essentially need to do is travel to the north-western district of Prague and use the sewers to reach the underground casino.

After sneaking into the casino, you'll need to make your way to Otar's (the mob leader) office on the top floor and hack into his safe to retrieve the calibrator. With the item in your possession, you can escape the casino and continue on with the main story mission(s). When you finally meet Koller, hand over the calibrator when he brings it up in conversation and the achievement will unlock.

NOTE: Completing this achievement will lock you out of Side Mission 04 and void the "Honor Holds Us All Together" and "All in the Family" achievements. To avoid this, simply make a manual save at the start of Mission 3 and after unlocking this achievement, reload your save and reach Koller without every having picked up the calibrator.