The Dynarette Guitar Cushion. This is the larger of their two sizes. It's meant as a playing tool for classical players to use on the left leg but it also works with archtops and plank guitars on the right leg as well. On a regular chair, both feet are on the ground. On a higher stool, I use it in conjunction with a foot rest at the lowest setting. It puts the guitar in a good playing position encouraging better posture and with nothing hanging from my shoulder, I can play in comfort for much long periods of time. After about 10 days with it, I'm pretty much sold. EDIT (12/05/15) Have a look at post # 14 in this thread for new information.