Square D LADN20 Tesys Auxiliary Contact Block Brand: Square D. Part Number: LADN20. Square D TeSys Auxiliary Contact Block, 690 VAC, 0.41 A, 400 Hz, 2NO Contacts, 1 Maximum Contact Block, Front Mount, 30000000/Mechanical Operating Cycles, -5 to 60 deg C Operating, For Use With: TeSys D, Schneider LC1F Contactor. Additional Description: SQD -LADN20 TeSys ADD ON BLOCK 2 NO -For D & F-MODEL IEC FRONT MOUNT. Catalog Description: TeSys Deca, auxiliary contact block, 2 NO, top mount, screw clamp terminals, for LC1D09 to LC1D150 contactors..