The MB-450-FOX is a #1.5 size trap but built tough and durable. Outside jaw spread is 5″ and inside jaw spread 4 3/8″. The 450 features 5/16 thick, smooth closed cast jaws. The trap boasts a Paws-I-Trip Pan, night latched dog heavy levers, features strong music wire springs, a #2 chain, crunch proof swivels, and a 2-piece gusseted frame for increased strength and reliability. We have had over 100 catches on one trap. They hold great and cause very very minimal fur damage.