Id never heard of this particular brand, but it had good reviews and ratings, so I pulled the trigger. 1) PXC 550, 2) QC 35, 3) MM 550, 4) QC 20Call Quality - Both the QC 35 and PXC 550 had great call quality to me. - excelente sonido- se carga rapido- es comodo al menos en mi oido. Bought these during prime day. Fits small. Busque muchas reseñas y opiniones en sitios dedicados y en cuanto a sonido inalámbrico son de las mejores opciones que existen; recomendaría que tu celular soporte apt-X para sacar mayor provecho. Size is consistent across the styles. 2 - The 2 spiral screws allow centering the bike from both directions when mounting so you can get the tire centered on the roller with enough tension on the quick release lever from both sides without squeezing the frame from only 1 side. if putting in the ceiling use in a stud area or add wood post with heavy duty butterfly screws if using to hang items weighing more than 50 lbs They fit great, are comfy and both stay on my heal while having room for my toes.