A retractable lock is arranged between a mounting desktop and a casing, a fixing clasp is arranged at two ends of the retractable lock.

在安装台与外壳之间设置有伸缩锁，在伸缩锁两端设有固定夹。

youdao

Under the new rules outlined this week, knives with blades no longer than 2.36 inches (6 centimeters) and less than a half-inch wide will be allowed in airline cabins as long as the blade is retractable and does not lock into place.

CNN: March 10, 2013 -- Updated 0334 GMT (1134 HKT)