It could be the Mountune "budget" 3 layer item, I would not be surprised if it was made to Mountunes spec by Cometic:

http://www.mountuneonline.com/acatalog/C84156.html

Head gasket - 3 layer Supersteel Ref: C841
This 3 layer gasket was developed as an alternative to the four layer WRC gasket. It features "fire ring technology" which results in increased sealing properties around the cylinder bore (compared to a standard gasket). This allows higher boost levels to be achieved.(RRP £225.00)

Price: £185.00 (Excluding: VAT at 17.5%, delivery and shipping)