Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: I'm looking to buy these. It does not specify if it is a single adapter shell or a pack of 4. Can someone please let me know.
Document: The rechargable batteries snap inside the shell. You get 4 of these in a pack. All you need isa penny to make them work once you load them in a Maglight flashlight. AA batteries do not have a large enough metal contact area on the end. The maglight coiled cap, therefore, fails to touch it. Just stick a penny on the end of the last battery in your maglight, and it seems to work very well. I'm very happy with my purchase.
You receive four (4) AA to D battery converters as picturedYou get what you pay for in this case. If you are looking to convert your standard 1.5 volt AA batteries this is an excellent option. If you are unaware, AA batteries are cheaper but D size batteries contain and maintain a longer charger.The product itself isn't very complex. It is essentially a plastic shell with no back. The shell will hold the AA so that it is level with the battery holder/ + and - ends.
If you have some power-hungry applications that require D-cells, you can usually save money in the long run by using rechargeable NiMH cells instead of alkaline cells. One approach is to buy a set of AA to D-sized adapter shells, and use rechargeable AA NiMh cells in those.
I ordered only 1 package sale $4.99 after that i read the review of MICHAEL SCHILLI: he mentioned that is wrong description because is only 1 plastic shell in the package?????????? MICHAEL SCHILLI IS WRONG.......i didn't ordered more thanks his stupid review now aren't on sale
They are not held in very tightly, so it's generally good to use a little care when inserting them into a device. Once they are in a device, they stay in place well. Removing the AAs is easy - just press on the popped-up metal contact on top, and the AA slides easily out the bottom.The adapter housing is very light and plastic, but seems well made. There's little stress on any part of the adapter in use, so I'm hopeful they will last a long time.
But this actually worked really well. I bought a smokeless ashtray that required 2 D batteries, and I saw these and thought I would give them a try. Rechargeable D batteries are hard to find, and I'm not real big on taking out a loan for rechargeable D batteries. Look up the prices, and you will see what I mean. This little adapter took care of the issue. I can use my current AA batteries.
So it's $6.99 for a single plastic shell? Seriously?How many adapters come in a package? One, as the product description seems to indicate? Or four, as there are four adapters displayed in the picture? Or two as one reviewer stated he received?Also, I seriously doubt that the weight of this package is "8 pounds" as mentioned in the product description. Are these adapters, like, from the future?
Insert 12" rod into smaller hole (grease up the part of the rod inside the PVC tubing with vasoline, aids in removal). Now squirt in some hot-melt glue in the void between PVC and rod all the way to the top. Let cool, and remove rod.FOR D-CELLS:  Cut 1.25" PVC into 2.25" lengths. Cut the 1/4" rod into 3/8" lengths.
I have these in a baby swing since buying a 4 pack of D rechargeables plus a charger was more than I wanted to spend. The product works as descibed, although it can be a little tricky to get the contact points lined up on the smaller sized AA battery. The biggest issue is battery life (which isn't a product flaw). The AA batteries drain in about 1/5th the time of using D batteries.
For uses that do not need the capacity of a D cell such as LED lights this product is the answer. I read reviews of other brands and chose this one for its simplicity and longevity. I bought these along with an LED lantern that requires 4 D cells. I too had the problem where the AA negative end was not big enough but I found the solution. My C***man lantern has 4 batteries in a pack instead of stacked end to end like a flashlight.
Answer: They come 4 to a pack.