This adapter cable converts your 4 Pin XLR cable to a 4.4 mm Pentaconn plug.  Most commonly used for connecting headphones terminated with a 4 Pin XLR Male to a 4.4 Pentaconn output from an Headphone amplifier or DAP audio source.  There are many length choices available to double as an extension cable.
 
The Pinout is as follows, also pictured above:

4 Pin XLR, Pin 1, L+: 4.4 Pentaconn Tip

4 Pin XLR, Pin 2, L- : 4.4 Pentaconn Ring 1

4 Pin XLR, Pin 3, R+ : 4.4 Pentaconn Ring 2

4 Pin XLR, Pin 4, R- : 4.4 Pentaconn Ring 3

4.4 Pentaconn Ground is Not Connected
 
All cable options include excellent dielectric insulation and shielding to reject EMI and RFI.
 
OFC Cable Specs
24 AWG Oxygen Free Copper conductors (4x per channel)
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 per channel)
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 per channel)
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 per channel)
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
 
4.4 mm Pentaconn TRRRS Connector Specs
Gold Plated Pure Copper Contacts
Carbon fiber and nonmagnetic stainless steel housing
 
XLR 4 Pin Connector Specs
Zinc diecast shell with locking mechanism
Gold plated contacts