Trucks come as a pair.

Size information:

143 – 7.125″ axle – for decks 7.4″ or smaller

145 – 7.62″ axle – for decks 7.4″ – 7.9″

147 – 8″ axle – for decks 7.9″ – 8.12″

148 – 8.25″ axle – for decks 8.12″ – 8.38″

149 – 8.5″ axle – for decks 8.38″ – 8.62″

151 – 8.75″ axle – for decks 8.62″ – 8.85″

161 – 9.125″ axle – for decks 8.9″ and bigger