On Wednesday, May 8, 7:30 UTC, maintenance will begin on the Caliber servers. The game will be unavailable.
试玩Caliber - 一款基于现实中特种部队的免费射击游戏。快节奏、紧张刺激的PvP和PvE战斗,多种角色扮演方式,干员个性化和养成。
Caliber Youtube channel