Việt
lỗ nhìn
lỗ quan sát
Anh
handhole
cleaning hole
Đức
Handloch
Putzloch
Pháp
trou de main
trou de poing
lỗ nhìn, lỗ quan sát
handhole /SCIENCE,ENG-MECHANICAL/
[DE] Handloch
[EN] handhole
[FR] trou de main
cleaning hole,handhole
[DE] Handloch; Putzloch
[EN] cleaning hole; handhole
[FR] trou de poing