The Exped SynMat HL MW is an ultralight insulated air pad in a wide (65 cm) version. Unlike the self-inflating SIM mats, it works on pure air-pad principles with Texpedloft synthetic insulation. An R-value of 3.3 (measured under Exped's older proprietary standard, not ASTM) puts it in 3-season territory, and 485 g is a fairly low weight for a 65 cm-wide pad.
The shell fabric is 20D polyester, the pad uses horizontal baffle construction, and two FlatValve fittings allow quick inflation and deflation; it's also compatible with a pump sack. A stuff sack and repair kit are included, with a 5-year warranty on materials. This model has been discontinued and is replaced in Exped's current lineup by the Ultra 3R, which offers a similar R-value at a lower weight.
For anyone considering this specific unit, it remains a functional, wide, 3-season insulated pad; buyers who care about current parts availability and the newest technology should look at the Ultra 3R successor instead.