In (I) and (4) the length is adjusted by turning the screw (usually with a tommy bar) and in the others by turning the sleeve; after adjustment, simple locking devices are used to prevent the screw or sleeve from moving further.
Ku (i) no (4) ubude buyandiswa ngokujekeleziswa isikrufu, kwezinye ngokujija umkhono emva kokwandisa ukuyila, ukuvala kusetyenziswa ekukhuseleni isikhonkwane ekushukumeni mgama.