Jan - they are 36 x 6". The basic white styrofoam or grey denser ones work, as do the softer ones. The softer ones are much appreciated by sensitive or thin or very tight muscle people. Look at the OPTP website //www.massagesupplies.com/product/1 0358/?gclid=CISpz-2svb8CFUEF7AodY0w AUQ. The only thing the soft ones don't work well for is the "knee stretch" (can't remember now if I did that on film) because once the weight of the body is on them, they don't roll easily (they're also textured and that probably has to do with it as well). I get my rollers from OPTP because they give a discount to pilates teachers!
Thank you, Ruth! Your class gave me great tips to remember for beginner teaching. I'm in a Pilates Teacher Training Program, Mat Level 1. I Loved your class.