Connector receptacle, panel mounting, 40 amp, 450 VAC, 3 phase with ground, watertight when the protective cap or mating plug is installed. SYM758.2 per MIL-R-2726/9. Military P/N M2726/9-002. NSN 5935-01-346-3019. Use protective cap, SYM1142.1, to keep out moisture, dirt and for safety considerations. Mates with plug, SYM717.1 per MIL-R-2726/3. Electrical connections made to solder cup terminals sized for #10 wire.