# Products by P-san☆ This is a custom-designed 40mm headphone speaker unit (driver). It's a replacement part used for headphone repair and DIY projects, compatible with several manufacturers and models. Type: Replacement/repair speaker unit (driver) for headphones. Size: 40mm diameter. Impedance: 32 ohms (Ω) or 33 ohms (Ω). Compatibility: It is said to be compatible with certain models of Bose QuietComfort (QC) series (QC2, QC15, QC25, QC35, etc.), AE2, OE2, SoundLink, SoundTrue, etc., but it is important to confirm the model and specifications before purchasing. These drivers are used to restore the original sound quality of the headphones or to customize the acoustic characteristics according to preference. K311 $$500