When I was relatively new to scene of fiber optic (a.k.a..dual fiber) makeup brushes - my curiosity was piqued from watching countless YT makeup videos, but I didn't (and still don't) want to shell out the $42 for MAC's 187 brush. Thus, I went looking for economical alternatives (i.e. dupes) of the infamous 187 brush, so I purchased Essential Beauty Supplies’ (EBS) Fiber Optic (dual fiber) Blush Brush for $8. Upon using the EBS fiber optic (dual fiber) brush, I quickly discovered that all the hype around the dual fiber MU brushes was true for you really do get an flawless finish when applying MU. Unfortunately, the EBS fiber optic (dual fiber) blush brush isn't very dense, the bristles are quite long and floppy, and it continues to shed ever time I washed it. In short, the EBS fiber optic/dual fiber brush is an OK brush, but my curiosity still wasn't quenched so I purchased the Lumiere Duo Fiber Optic Brush which I absolutely adore (please see my review on this brush).
By the way, this is Fiber Optic Brush which is manufactured and also sold by Crown Brush (and if you have read my other review, then you know that I love Crown Brushes for I have over 12-15 Crown MU brushes), however this brush is just not up to par.