To be honest with you this is a piece of equipment I originally skipped out on during most of my first round of P90X. I ended up using my push-up stands/bars in place of a Yoga block. But about half way into Phase 2 I got serious about Yoga and spent the 10 or so dollars on an actually Yoga block. There are a number of brands, materials, and looks out there but I really believe any of them will most likely fit the bill. A Yoga Block is really just an extension used as support or for more of a reach during Yoga. Either a way, it is a crucial part of helping you develop the right form, technique, and strength to continuously progress your Yoga game.
Again, I went the inexpensive route and got this Gold’s Gym Yoga Block….but, if you’d like to step up your Yoga Block game I’d recommend some of the wooden blocks…those can be very beautiful.