This handy tool from Denago works perfectly on City Model 1 eBikes. The tool is included free with Denago City Model 1 purchase, but is also available separately to replace a lost tool. It can work on other makes and models, too! 

This tool features 15mm open, 18mm open, and 15mm closed fittings which can be used to install and remove the front wheel, rear wheel, and pedals on Denago City Model 1 eBikes.