School grade - 5!

The ProSilent Ceramic S, what holds not promise the product images from JBL.
No trace of microbubbles. Rise to large blisters on a handful of sites.
Every 08/15 - 1 vent makes just as good, if not better.
I trouble myself about buying.

Youtube> OHjaNpKkDYw

In addition, the vents barely holding the suction cup.
The provided pin is way too small.
A little touch is enough, then go sucker
and vent their separate ways.

Clearly, here, there is no recommendation!

Edit:
Now I have a vent from linden wood by Sander for ~ 2
and a good result.

MfG