We can determine the heat capacity of the wrench by looking at the information given and the units we need for the answer. Remember that heat capacity is for a specified object and has units of J/degC. Specific heat has J/g degC. Heat capacity is typically used for an object of fixed mass while specific heat is used for elements/compounds that can change in mass more readily.
q = C(deltat)
where q is the heat, C is the heat capacity and deltaT is the change in temperature. We can plug in the values we know (converting kJ to J)
2.48 x 10^3 J = C(21 degC)
C = 118 J/degC
Now that we know C, we can use the mass of the wrench to determine the specific heat by dividing by the mass
C/mass = s
where s is the specific heat.
118 J/degC / 650 g = s
s = 0.182 J/g degC
Alternatively, we could use the formula
q = m s deltaT
and solve for s (specific heat).