This is the third cord bit I've bought from you guys the last one was a 2.5" I've used very little the other one was a 3.5" and after going through my foundation twice it's down to 1 tooth, so that's why I bought this 4" bit, the only problem I've had is trying to keep my drill from submerging from the excess water, before I was standing in my shop drilling out so I had plenty of drainage, this time I'm in the drainage ditch drilling as close to the bottom as possible, I don't have enough space for my pump to work the drill eats all that up, I guess I'll have to wait untill I finish trenching so I'll have more space in the hole are pull my kitchen cabinet so I can but it at an angle from up top, anyways you guys make a great affordable product, thanks, Rick