Ottobock ??????????????????????????? ?????? ?????????????????? ?????????????????? ?????????????????? ???????????????? ????????????????????????????????????????????????????????????????????????????????????????? ???????????????????????????????????????????????????????? ???????????????????? ??????????????????????????? ?????????????????????????? 15-25 ???
แผ่นกรองอากาศต้องมีกี่ชั้นกันนะ ถึงจะสามารถกรองฝุ่น PM 2.5 ได้
?????????????????????????????? ???? ????????????????????????????????????? ????????????????????? PM2.5 ????????????????????? ????????????????????????????????????????????????????????????????? ??????????????????????????????????????????????????????????????????????????????????? ????????????? ???????????????????????????????????????????