Travel Technology - Need to replace "old school" IPOD

I have an old school 15GB IPOD that just quit. Lasted 4.5 years..can't complain.
Anyway, I have the Bose Sound Dock and I need to find an IPOD that fits into the base ....I like the size of the Nano..but how does one make it fit into the Sound Dock? Can it? Is there a different base that I can buy in order to ensure that it fits?
Any advice is appreciated

Most iPods have the standard Dock connector on the bottom. Any device that utilizes a Dock connector for audio-out purposes (like your Sound Dock) will work with any iPod (with a Dock connector).

So a new Nano will fit in the slot, but there may be a little extra space. Some companies sell "dock adaptors" to fill the gaps, but this really is only an aesthetic improvement.

Bose makes little adaptors that fit any iPod. Just ask them online or find a store and they will take care of it for you. My husband must have registered his cause I think they just send him new adaptors every time there has been a change in the iPod connector.