Level 1	Voice Level 1 cables are manufactured to meet minimum telecommunications cable requirements. Typical uses include analog and digital voice plus low speed data (20 kbps).
Level 2	ISDN and LOW Speed Data These cables support the IBM Type 3 Media requirement. Most uses are defined through the IBM Cabling System guidelines. This specification defines electrical requirements through 1 MHz.
Level 3	LAN & Medium Speed Data These products support the ANSI/EIA/TIA-568 Commercial Building Telecommunications Wiring Standard specification horizontal cable (also known as Category 3). This standard defines cable performance through 16 MHz and thus supports high speed LAN applications.
Level 4	Extended Distance LAN Level 4 cables are specifically designed for LAN applications. Most UTP LANs require a higher degree of performance than the standard telecommunications design offers. Level 4 cables require performance testing through 20 MHz and provide outstanding crosstalk isolation and attenuations. They are ideal for extended distance 10BaseT (<=135 meters) and 16 Mbps Token Ring.
Level 5	High Speed LAN 100 OHM This level requires the ultimate design for 100 ohm UTP cable. These cables are intended to be used up to and including 100 Mbps CDDI applications. High Speed LAN 150 OHM - DGM The 150 ohm shielded twisted pair (STP) data grade media is the cornerstone of the IBM Cabling System. In addition to the many IBM applications, this cable is now supported by a consortium of 5 system vendors for 100 Mbps twisted pair transmission until the ANSI X3T9.5 standard is completed.

This applies to:

TokenExpress™ 16/p Adapter TokenExpress™ EISA 16/4 Adapter TokenExpress™ EISA 32 Adapter TokenExpress™ MCA Adapter TokenExpress™ PRO LAN Adapter