Telect’s HS+ terminal blocks do not use the industry standard wiring for pin pairings.  For example on a 25-pin connector, the industry standard pin pairs for a terminal block are 1 & 26 for pair one (1) and 2 & 27 for pair two (2) on the connector.  However, In order to achieve the higher speed ratings on a High Speed Plus block (HS+), Telect will use adjacent pin pairs to keep a tighter wire wrap at the connector.  On a 25-pin HS+ connector,  Telect terminates the pair one (1) pins to pins 1 & 2, and pair two (2) pin pairs on 2 3 & 4.  This is done in order to reduce insertion loss, return loss and cross talk by keeping a maximum of 1/2  in. twist ratio prior to termination. Furthermore all HS and HS+ terminal blocks internal are built with Cat5 wiring standards and require the use of Cat5-25 pair connectorized cabling to achieve the higher rates.