ALVIS Mk4 earplugs (SNR: 27 dB) technical characteristics:
Valve open or closed:
With the valve open, the filter acts continuously depending on the acoustic energy it receives. So you can remain in contact with the outside environment, take part in a conversation, make a phone call… constant noises that are too loud will be reduced to a comfortable volume, and impact noises will be reduced instantly. The noise attenuation values according to EN352:2 are:
SNR: 19 dB H: 22 M: 16 L: 11 dB
When the valve is closed, the filtration is identical at all frequencies and permanent, the Mk 4 becomes the equivalent of an occlusive Mk 2. The occlusive mode is recommended for sleeping, swimming and working with a constant high sound volume. The noise attenuation values according to EN352:2 are:
SNR: 27 dB H: 28 M: 24 L: 24 dB
ALVIS Mk4 is a very high-performance and cost-effective noise protection plug: it is used by many employees of industrial companies.
Half-attenuating earplugs with helix available in 3 sizes
The helix of the ALVIS Mk4 earplug ensures a perfect fit in the ear in all circumstances. It is made of silicone, is very soft and cannot be felt. It allows the earplugs to stay in place without putting pressure on the ear canal, so they can be worn all day without discomfort.
To ensure comfort, fit and sound insulation for all ears, ALVIS Mk4 earplugs come in 3 sizes (S-M-L). The flaps and helix are proportionally sized to fit the size of the concha (hollow part of the pinna) and the ear canal.
How to choose the right size?
Measure the size of the concha of your ear as shown in the pictures above. The concha is the hollow part of the ear where the helix of the earplugs will be placed. Less than 2 cm: size S, from 2 to 2.5 cm: size M and more than 2.5 cm: size L.
How do I put them on correctly?
The earplugs have an orientation that is marked (on the side of the helix) R for the right ear and L for the left ear.
Insert the transparent silicone earplug into the ear canal by pressing the round part. You can rotate the earplug a quarter turn while pressing it in to make sure it is securely in place.
Place the helix in the shell of the ear so that the earplug cannot move, it must conform to the shape of the shell of your ear. This part of the earplug has no effect on noise attenuation, but ensures that it stays in place.
Should they be tested before use?
The earplug must provide a perfect seal. If it is not properly seated, the attenuation will lose much of its effectiveness.
To make sure the seal is perfect, slap it close to the ears. A slap generates a lot of noise and should be significantly dampened.
If it is not muffled, the earplug needs to be adjusted or is the wrong size.
How do I clean ALVIS earplugs?
Clean your ALVIS earplugs with soap and water. Let the earplugs air dry and store them in their waterproof box.
What is the shelf life of the earplugs?
ALVIS Mk closures can be used for 18 to 24 months, and some of our customers who use them occasionally keep them for several years.
To extend the life of your earplugs, keep them free of dust and prevent them from getting dirty.