I didn't know that my Lexus ES 350 "smart key" that does everything from starting the car to unlocking the doors was battery driven until my car started warning me it was going low. Uh, oh.
I looked up the warning in the manual, got the right battery number and then searched every store I went into - grocery stores, drug stores, Target... No one carried it. Then, the battery died on me.
So, I needed one pretty quickly. I'm not sure why the other reviewer says that shipping is expensive. It's free (without even spending the normal $25 typically required by Amazon) if you can wait three to five business days. But, I needed mine immediately. So, I paid the Fed-ex cost, which seems to be the actual Fed-ex cost. This is the only supplier I could find on Amazon that offered multiple shipping options on it (1-day, 2-day and 3-day and longer). So, it was the best option for me as long as they sent out the right thing, quickly. They did.
I ordered four to keep the extras in my glove box, so I won't get stuck again. But, the cost of the shipping was the same as for one. They came in a four strip Panasonic sealed package, and work just fine.
This is the only way I'm getting my batteries from now on. Only, I'm going to do order them earlier.
TIP: There's a youtube video someone put together to show you how to change the battery in your smart key that I found more helpful than the manual.