Hopefully someone else can confirm but..
If you have the SP or FS then you need;
Front wheels : Model number KW5201W
http://www.microtechracing.com//prod...cat=LAZER+ZX-5
Rear wheels - Model number W5204W
http://www.modelsport.co.uk/?CallFun...n&ItemID=34017
(I couldn't find the rears on the microtech site
If you have the standard lazer then its;
Front wheels: Model number W5026W
http://www.modelsport.co.uk/?CallFun...n&ItemID=18972
Rear wheels - Model number W5204W
http://www.modelsport.co.uk/?CallFun...n&ItemID=34017