I have a nice original Speer 4x4 SPE (Segmented Pad Extender) for sale. It is used to extend a standard 20" sleeping pad with up to four 5"x20" CCF pads, cut from your blue foam pad (not included), so your shoulders and hips are insulated. It can be used with just 2 pads or whatever combination works for you. It has a mesh insert down the back to help keep it from slipping. No longer made, in excellent condition, 4.6oz. $40 including shipping to US addresses and PayPal fees.