This model uses the Anker PowerCore 5000mAh and a 0,5m Apple cable to be wrapped around. The grove on the model is fitting for the Apple cable and its diameter. However, any cable with a length of around 0,5m should fit as long as the diameter is about 2,8 mm. 

In case you use this model than make sure to sand the inside of the model down, if necessary. The powerbank should slide in with light force application don’t force it in. The powerbank will expand a little when charged this could damage the model or worse the powerbank itself.