Symbio W is made of silicon outside with memory foam eartips, specially in hybrid materials for In-Ear IEM earphone.

For In-Ear Monitor IEM earphone, with stem diameter from 4.5mm to 6mm.

Outside diameter:

• Small S: 11mm
• Medium M: 12.59mm
• Large L: 14mm

Compatible earphones: Pls refer to attached picture. 

What's in the box (Pls select from different options) ? 

• Option (1) : 1 Pairs (2 pics) of eartips for same size
• Option (2) : 2 Pairs (4 pics) of eartips for same size

Why is Symbio different ?

Great seal of memory foam with longevity of silicone. The foam has a real gentle force to push the silicone to the wall of your ear canal. In this way, eartip will pick up the shape of your ear canal. That means tending to perfect isolation.

No more seal problem caused by shallow insertion!

You need the best isolation to get the most from your earphones. Symbio will help you in this. Soft memory foam (instead of sponge, as in oder hybrid tips …) lives in perfect symbiosis with flexible and durable silicone.

Review on Head-Fi: https://www.head-fi.org/threads/a-review-of-mandarines-foam-tips.825397/page-4