L-com carries 70 different spools of telecom/modular bulk cables, everything from Flat Modular (also called Silver Satin or non-twisted modular), to Category 3-, 5e-, and 6-rated unshielded twisted pair (UTP) and shielded twisted pair (STP), to T1/E1 individually shielded twisted pairs.  So how do you know what you need?

Jacket Types
The jacket is the outside material of the cable, which covers and protects the individual conductors within.  While the jackets can be one of several colors, the actual material composition may be important to your application, particularly the flammability rating of the jacket (video).  The four jacket types available are:

• Poly-vinyl chloride (PVC) –For most general situations
• Plenum (FEP) –Designed to self-extinguish in the event of a fire, often used in public buildings to comply with fire codes
• LSZH (Low Smoke Zero Halogen) – Does not contain poisonous halogen-based compounds, which can be released when burned, making this the choice for special applications like airplanes and submarines
• Polyurethane (PUR) – A rugged material preferred for industrial environments where it could be exposed to friction and oil debris

Conductor Sizes
Conductors are usually sized according to the American Wire Gauge standard (AWG).  The standard runs backwards, so a 22 AWG conductor is much larger than a 28 AWG conductor.  In general, the gauges work well with the following conductor sizes:

• 22 AWG – The largest available for UTP cables
• 23 AWG – The standard size for Category 6 cables
• 24 AWG – The standard size for Category 5e cables
• 26 AWG – The typical size for any Shielded (STP) cables
• 28 AWG – The smallest size available for UTP or STP cables

Conductor sizes are important because not all modular plugs are made the same.  The ability to terminate a conductor into a plug or jack is limited and you should always make sure that the cable and plug you intend to use are compatible with one another.