Fingerboard wheels typically come in 3 sizes: mini, standard, or large; verbiage may vary between brands. Each size does have its benefits and drawbacks, but ultimately, it comes down to personal preference. Mini or small wheels will keep your deck lower to your riding surface which will make pops not quite as high but will keep the board more level for flip tricks. Larger wheels will require more force to pop due to the deck being lifted higher, which will result in higher pops but a bit less control in flip tricks when learning. Standard is right in the middle and will give medium pop and medium control for all flip tricks; most wheels on the market come this size.