4 公釐口罩鬆緊帶，白色，3 碼

The 4mm width is perfect for my homemade masks—tight enough to hold but still comfortable behind the ears. It’s also held up fine after several machine washes without any fraying.

I've already washed these a couple times with my homemade masks and they haven't frayed or lost stretch at all. The 4mm width is a good balance—thin enough to be discreet but wide enough to be comfortable for long wear.

I was worried about the elastic losing its stretch after washing, but after three runs through the laundry it's still soft and snug. The 4mm tube construction sits flat against my ears without that irritating pinch. Finally a mask elastic that actually holds up to daily use.