This adapter cable converts your 2.5 mm TRRS plug terminated cable to a 4 Pin XLR Male plug.  Most commonly used for connecting balanced headphones terminated with a 2.5 mm TRRS plug to a 4 Pin XLR balanced output from an Headphone amplifier, DAP or DAC audio source.  There are many length choices available to double as an extension cable.  This cable transmits a balanced stereo signal.
 
The Pinout is as follows, also pictured above:
 
2.5 mm Tip, R- : XLR Pin 4
2.5 mm Ring 1, R+ : XLR Pin 3
2.5 mm Ring 2, L+ : XLR Pin 1
2.5 mm Sleeve, L- : XLR Pin 2
 
All cable options include excellent dielectric insulation and shielding to reject EMI and RFI.
 
This Cable is available in OFC, SPOFC, OCC & Pure Silver.
 
OFC Cable Specs
24 AWG Oxygen Free Copper conductors (4x)
High density braided copper shield.
PE dielectric insulation.
PVC Outer Jacket
Outer Cable Diameter:  6.3 mm
 
SPOFC Cable Specs
20 AWG Silver Plated Oxygen Free Copper Conductors (4x)
High density braided copper shield.
PTFE Teflon dielectric insulation
FEP Outer Jacket
Outer Cable Diameter:  5.8 mm
 
OCC Cable Specs
24 AWG Ohno Continuous Cast conductors (4x)
PE Dielectric Insulation
High density braided copper shield.
Aluminum Foil Shield
Double Layer Outer PVC Jacket
Outer Cable Diameter:  8.4 mm
 
Pure Silver Cable Specs
27 AWG Pure Silver conductors (4x)
FEP Inner & PE Outer Layer Dielectric Insulation
High density Silver Plated braided copper shield.
Aluminum Foil Shield
Double Layer Outer PVC Jacket
Outer Cable Diameter:  8.4 mm
 
2.5 mm TRRS Connector Specs
Gold Plated Pure Copper Contacts
Carbon fiber and nonmagnetic stainless steel housing
 
4 Pin XLR Male Connector Specs
Rhodium Plated Pure Copper Contacts
Carbon fiber and nonmagnetic stainless steel housing