Specification:
1.Removes broken screws, bolts, and studs without damaging bolt or hole threads
2.Material:alloy steel,HSS,carbon steel
3.Sizes available as follows:

• 3/32-inch to 5/32-inch Screw Size Extractor
• 5/32-inch to 7/32-inch Screw Size Extractor
• 7/32-inch to 9/32-inch Screw Size Extractor
• 9/32-inch to 3/8-inch Screw Size Extractor
• 3/8-inch to 5/8-inch Screw Size Extractor

Other sizes are also accepted according to your requirments. 
4.Surface treatment : Zinc coated, black oxide, tin-coated.
5.5 pcs extractor set,other set are also available.
6.The screw extractor  generally  works with the left hand drill. 
I am looking forward to you kind inquiry.