I use an Echo for my Levemir and it's great, so I tried to fit my Apidra cartridge from Aventis into it but no luck. I use the Lilly Humapen Luxura HD for my Apidra because for some crazy reason Aventis don't make a half unit pen. I prefer the Echo because of the memory thing but it doesn't even get close to taking Aventis cartridges
Smidge