Maybe you remember these great Face Protectors, better known as "Bull Bars", that Casio made in the past to make DW-5600's and DW-6900 look quite tougher. They seemed sold out for a long time at Casio, but a third party manufacturer has made these Bull Bars available again. They are sold by Tiktox in the UK. If you live in the UK, the price is great. For £12.- you can order one and it's shipped free to your home. Of course Tiktox does ship outside the UK.
DW-5600 Face Protector
DW-6900 Face Protector