OEMTOOLS 24377 35-Piece Master Screw Extractor & Drill Bit Set - Professional Broken Bolt Remover Kit for Automotive, Plumbing & DIY Repairs

As another reviewer noted, this appears to be the plain jane version of the IRWIN Screw Extractor/ Drill Bit Set, 35-Piece (11135ZR). The quality of the drill bits and extractors appears to be the same, you just don't get the fancy reference card, that tells you which drill bit and extractor combination to use for a given bolt or nut. And it's much cheaper. The blow molded case is hinged with a metal pin, which is nice. No worries about it fatiguing from frequent flexing, and then breaking. The case does not have any labeling for part placement, however; I used a black Sharpie to label mine. The case dimensions are 11.5"x7.5"x2". The extractors are laser etched with the required left hand drill bit size, though the etching could stand being darker, for better contrast.The extractors themselves work extremely well, I used two to remove the remains of three broken spark plugs in a Dodge Caravan 3.3L engine. I did have to add a ton of heat, via an oxy-acetylene torch, but once I got them red hot, the extractors bit in and they came right out. I did not need to use the included left hand drill bits. FYI - if you are getting these for this type of work, I would recommend draining the engine coolant. Otherwise, you will never get the plug remnants hot enough, since the aluminum cylinder head and coolant inside act as a massive heat sink, and prevent it from heating up like you need it to.