The Mac Tools Exhaust Stud Remover, No. XMSR1 features a compact design and works on studs as short at 1/4". It includes four collet sizes: 1/4" (6mm), 9/32" (7mm), 5/16" (8mm) and 3/8" (10mm). Engineered and manufactured for extreme tightening, the XMSR1's hex design allows for tightening in tight places, and its collet design keeps the tool secure on a broken stud without tipping. According to the company, the stud remover is perfect for exhaust manifold studs and offers a lifetime warranty.