The MB-550-CL Four Coil Spring Cast Closed Jaws Trap has an outside jaw spread of 5 1/2" and an inside jaw spread of 4 3/4".  The cast jaw face is 3/8" thick.  This trap has a Paws-I-Trip pan system and a night latched dog.  Pan tension out of the box (un-waxed) runs an average of 3.1 pounds.  Due to the additional power provided by the 4 coiling, this trap is not recommended if grey fox is your target animal.