http://www.e-a-r.com
i buy 1 ear plugs made by AEARO company Indianapolis, USA.
the price of ear plugs AEARO jakarta is 10000 rupiah per one.
AEARO easy to plug into ears and easy to take out from ears.
E-A-R UltraFit noise reduction rating 25 dB good reduce noise.
to improve better ear plugs, i suggest to make better ear plugs:
shall make from a better material so not easy to break eardrum.
suggest design eardrum change to solid for strong not damage.
a solid ear plugs design: inner hard material, outer soft material.
must have holder + stopper to stop plugs get into ears too deep.