Mono hydraulic Pillar:
Tsuas yog hu ua hydraulic prop, nws yog txawv ntawm kev txhawb nqa hydraulic, uas tsis muaj lub cuab yeej thawb, feem puag thiab ru tsev nqaj.
Cov qauv ntawm ib kem yog qhov nyuaj dua, tab sis nws yog qhov tsim nyog rau cov kab rov tav uas yog cov khoom siv ua haujlwm tau yooj yim lossis cov khaubncaws sab nraud povtseg.
