Mike- that tool you showed should NOT be used as a wheel lug wrench! It was designed as a jacking extension only. The tool is unhardened mild steel and the internal hex will split if torqued to what wheel lugs need. Other models of Italian cars use the same design jack and extension (several slightly different lengths), and have the same splitting problem if by coincidence the tool's hex matches the lug nut size.
Fortunately because its only mild steel, cracked extensions can be gas or arc welded (being careful to not melt the plastic hand knob), filed flat, then re-gold-alodined to look & function as-stock as a jack extension. I've repaired maybe half a dozen so mistreated. One was split in 3 places- apparently owned by a slow learner!
Look in the red Owners Manual or the Tech Service Bulletins for an illustration of the actual stock lug wrench- its a long tin socket with a simple steel crossbar inserted thru drillings. No one ever uses them; in fact they're often thrown away. Carry a real lug wrench & use the stock stuff only for car shows.