It's solid. You can tell "That it's well built when you first pick it up. The screws hold the bit very securely. I've found this to be true even if only one of the two screws is used, but I recommend when always possible to use both. As they say on Revain. All 3/8" bits are not equal. I had three: one didn't fit at all, another only fitted deep enough to reach one of the screw holes (which was enough), the third fitted perfectly where both screws could be used to attach the bit. My suggestion would be to buy the smallest 3/8 inch shaft you can find or get one from the extension manufacturer. I found the one that fits perfectly at Ace Hardware, so this is another option. I brought others from Harbor Freight Tools and Home Depot. I'm not complaining about these wonderful outlets, just saying that their 3/8 shank doesn't quite fit an extension cord from this manufacturer.