Telect's 009-6212-2100 panel uses 5/16" studs on 1" center, and can support up to 4/0 AWG cabling.  In addition, the 009-6212-2100 panel has a maximum width requirement on the input lugs of 1.03". 

Telect does not sell any lugs for 5/16" studs on 1" center directly, but there are many options available from Burndy, T&B, and Panduit.  Most 5/16" studs on 1" centers from these vendors only go to 3/0 AWG cables, but a 2-hole 3/8" lug on 1" center would also fit the 009-6212-2100 panel.  Some examples of a 4/0 AWG 2-hole 3/8" lug on 1" center include:

·         T&B 256-30695-1261
·         Burndy YA28L-2TC38
·         Burndy YA282TC38