I bought this parts kit when I ordered a package from from ANS. If you own an A-5 you'd be a fool not to pick up a spare parts kit. This has all of the "bread and butter" parts that will likely fail at some point in the life of your marker. It's also nice for storing all of the extra parts and some tools you'll aquire when you modify your A-5. You'll be glad you spent the $10 when your receiver O-ring breaks, but you can fix it quick and get back into the game.
Smart buy. 
