This is a 3d-printed case in the size of the original Metz 60 series dry-fit battery for Mecablitz 202/502, 402/56-1, 60 CT-1/2/4 etc. 

The case can be filled with either the original batteries (NiCd C cells (~D25 x 46 mm), shown in the photos for info, not included), or other types of batteries (for example Li-ion 26650 or 18650 with the appropriate BMS controller, you can find information online and choose how to do it).

Internal dimensions are about 5.5 cm x 5 cm x 7.5 cm (larger that the NC-akku 60-39, shown in the photos for comparison, not included), and there is extra space at the top and bottom for a small controller board. 

The adapter is sent as a kit to be assembled. This way it fits in an envelop and minimizes sending costs. Assembly is straightforward, the side and rear walls clip into place (and can be glued if desired, although it is not necessary). The front wall is screwed into place so that the case can be re-opened. All connectors, cables and screws are provided, as shown in the photos. You only need to get the batteries and assemble (yellow cable--> +, blue cable --> -).  

See here for an adapter that takes rechargeable AA batteries: https://www.ebay.nl/itm/234838866498

Shipment costs are for normal, untracked mail. PostNL offers a reliable service. Upon request I can offer a registered, tracked service, please contact me for the exact cost. Buying with the standard shipment method is accepting that no tracking information can be provided.

Please keep in mind that this is a private sale, and that you are buying a second-hand, old camera equipment, which I have tested to the best of my ability and cannot provide any guarantee for or accept returns. 
Buying, selling and sending such objects is a delicate process, which must end with your full satisfaction. So please contact me in case you have any questions, I am happy to address them. 
For non-EU buyers, please note that import duties and other taxes are not included in the item price or the shipment cost. The buyer is responsible for these charges.