Square D™ and trade, 8501 NR sockets are designed for use with plug-in 8501 K and type R relays, 8430 MPS phase failure relays and 9050 JCK timers. The 8501 NR45 screw terminal sockets have pressure wire clamps that accept 1 or 2 #22 to 16 AWG wires. All other sockets have pressure clamps that will accept 1 or 2 #22 to 12 AWG wires. The recommended tightening torque for all terminals is 7 to 8 in-lb.