We’ve posted a lot of deals in the past on these coccyx seat cushions, but $12 is one of the best prices we’ve seen to date. If you aren’t familiar, you just put this under your butt on your desk chair, your car seat, or anywhere else you spend a lot of time sitting, and it can help improve your posture and ease chronic back pain. Just be sure to clip the 40% coupon to get the deal.