You need additional Parts:
2 Bearings 608 ID 8mm OD 22mm W 7mm (skateboardwheels)
1 15mm rod (end turned down to 12mm)
1 M8 treaded rod about 200 mm
1 M8 x35 bolt
1 M8 Nylon nut
some M8 Washers
2 M6 nuts
2 M6x20 Allenkey bolts
you can use a Fitting spring if you have one.
i use a Mercedes Benz spare part # 442 993 51 01 this should be easy go get and cost about 1€