I found this little yocan kodo pro by chance and i love the how descrete it is. This guy works well with all types of cartridges, with a varying ohm that automatically detects which ohm would be best for each type of cartridge. This battery also comes with a self adjustable voltage control from 1.8V-4.2V, which allows for a huge range to find the right voltage for you, for the type of cartridge you have. Every battery comes with either a finger or wrist lanyard. Leave a note for which one you would prefer.