Qhov ntau thiab tsawg cov tsheb kauj vab feem ntau muab faib ua peb pawg (axis nrug X nti):
1, 1/2 "X 1/8";
2, 1/2 "X 3/32";
3, 1/2 "X 11/128".
Cov saw loj ntawm cov kis las nce mus nce tsheb ceev ceev yog pib 1/2 "X3 / 32" thiab 1/2 "X 11/128";
Ntawm lawv, txoj saw saum toj 9 ceev feem ntau yog 1/2 "X11 / 128", thiab qhov nrawm ntawm 8 nrawm thiab qis dua feem ntau yog 1/2 "X3 / 32".
