Normal parasols and umbrellas have minimal flexibility - you can’t really tilt them to alter the cast of their shade. By contrast, a cantilever parasol can flex it’s ‘hood’ away from the stand, to lend its shade to where you want it to go. Cantilever parasols have the benefit of flexibility, the trade off is that normal parasols are generally sturdier (if you live in an exposed, windy area, this is a consideration). What size should I go for? At least 2 metres, to ensure a reasonable cast of shade. 2.4 metres is industry standard. Of course, if you have a larger backyard, go for something a little wider.