These bolt-on hub extenders with wheel adapters allow you to add about 2" of backspace to your wheels, so you can in many cases avoid the expense of custom wheels, and use wheels with less deep dish.
The part on the right goes on your hub using open-end lug nuts. The part on the left goes over the part on the right using 8 mm Allen-head bolts, like in second photo. All MUST be torqued to same spec as recommended for your lug nuts.
NOTE: Datsun wheel studs are typically 12x1.25 threads. The studs on these hub extenders are 12x1.5. There are four 12x1.25 open-end nuts supplied with each hub extender/adapter, and five 12x1.5 open-end lug nuts. DO NOT USE THE 12.5 NUTS TO HOLD THESE ADAPTERS TO YOUR DATSUN HUBS. If you attempt to do so, you'll potentially ruin your threads.
Sold in two-piece set, which includes open-end lug nuts to attach the adapters to your car. Lug nuts for your wheels are NOT included, and should be selected to match your wheels. Your wheel vendor should be able to help get exactly what you need.