UPDATED REVIEW (05/2019): Okay, after trying these bits last year I downgraded my rating from 2 to 1 star. These beats are just complete rubbish. They detach from the hex almost effortlessly, rendering the racquet useless and the material too soft for anything other than soft MDF. without bending the beat. Don't waste money. they are too unpredictable even as single use bits 1-2. You don't even get 1 use from them. OLD REVIEW (07/2018): Very low price per bit and you get a good range of bit sizes, but as others have pointed out these bits are extremely low quality. I've used them primarily on MDF and found that the bits lose their sharpness almost immediately. In addition, they are soft, so with very little effort they show flexibility and deformation and tend to walk on the surface. Given the price, they might come in handy for a simple weekend project, but be prepared to toss each piece in the trash after 3 or 4 uses.