Tus qauv ntawm lub snap khawm yog txiav txim siab los ntawm qhov loj ntawm peb daim tom ntej, thiab cov qauv siv feem ntau yog 655, 633, thiab 831.
The three BCD pieces are generally referred to as "the next three pieces". The surface of the snap button (A piece) can be changed at will, but the next three pieces generally have their general rules.
Qhov qis dua peb daim ntawm tus qauv 655 tuaj yeem sib phim nrog buckles nto nrog ib txoj kab uas hla tsawg dua 10mm;
Qhov qis dua peb daim ntawm 633 qauv tuaj yeem ua ke nrog lub ntsej muag buckle nrog txoj kab uas hla ntawm 11-15mm;
Qhov qis dua peb daim ntawm tus qauv 831 tuaj yeem sib phim nrog buckles nto nrog txoj kab uas hla ntawm ntau tshaj 15 hli.
