They are simply designed mdf card holders that also allow you to track the loss of hull points value as your vessel takes hits.
Starting at £2 each (for a pack of 4), the price drops the more you purchase (£1.50 each if you buy 6). This price includes post and packing and, as you can see from the picture above, they come well packed. Time from placing the order to arrival was just 5 days.
A little assembly is required but it's not a big deal and instructions are included. The main parts come on two mdf sheets, the parts push out cleanly and you can glue them together with either PVA or (if you're in a rush!) SuperGlue.
The rings that slide over the hull points values come in a separate bag. Be careful to let the assembled sliders dry completely before completing assembly to ensure they can slide smoothly.
It's your choice whether you paint the finished item. I chose to just paint the rings red to help them stand out a bit more, but left the rest. If you turn the finished card holder over, there is a window cut out to reveal the points values printed on the card's reverse.
I rather like these. I think they are practical, good value and will prevent the cards coming to harm. The slight raised edge will also avoid damage counters ending up on the floor if the table gets knocked accidentally!