First off, I need to point out the desoldering "blade" tips like this are *incredibly* hard to find at a reasonable price. They are easy to obtain for metcal soldering stations, but those start at $1,000 and the blades are around $80 each. Weller only makes blades for their most-expensive top-of-the-line soldering station, and again it's an $800 station and $70 blade.So it's sort of a small miracle that this guy is selling desoldering blades here for such a reasonable price. I'm grateful.With that in mind, I need to point out that this blade has a lot of flaws -- but it's still a great deal.1. The shaft of the tip is missing the "collar" that holds it in the soldering iron handle. You're supposed to unscrew the top of the handle, insert the tip, then put the top back on OVER the tip-of-the-tip and screw it back in. Unfortunately since the blade is much larger than the hole in the end of the soldering iron top, that won't work. I think that's why this tip has no "collar". The problem is that there's nothing holding the blade in the iron except friction -- if you grab the blade and pull it will pop right out of the iron (kinda like Metcal tips, except they're designed to do this).2. NEVER EVER EVER use the blade on a device that has flux on it. You MUST clean off the flux first. Whatever this blade is made of, when it comes in contact with flux the flux immediately forms an unremovable black tar on the blade and the blade starts malfunctioning (the soldering station shows "UUU" which means "tip heating element failure"). No joke, don't even do this once, it will immediately ruin the blade. I've never seen any other soldering iron this sensitive, and I've always been able to clean them -- but once this one is damaged it will give you the "tip failure" error even if you clean it off.3. The blade rotates freely within the iron handle. This is really annoying. If you place the blade flat on a surface and then rotate the shaft, instead of pressure being applied on one side of the blade, the tip simply rotates within the soldering iron handle. ARGH! This is a consequence of the tip not having the proper "shoulder" or "collar" to hold it in place.So, if you keep all this in mind, the tip is still a great deal -- less than a quarter of what you'd pay for other soldering blades, and it works on a soldering station that costs 10% of any other station with blade tips. You just have to know what the flaws are and work around them.Last bit of advice: if you're desoldering the balls from BGA chips, use a pre-heater. BGA chips are designed to conduct heat very well from the center balls to the top of the package (through the die), so you'll find them impossible to remove -- the chip will just sink away all the heat from the iron. You have to bring the entire device up to ~150C to keep it from acting as a giant heatsink for the balls.