Extra Firm is the level of support to the body, suitable for extra heavily weighted people. This is not a comfort rating.
Open Coil are Bonnel springs in an hourglass shape, joined creating an open coiled mattress.
Mattress Depth 24 cm
One Sided mattress, no need to turn this mattress, but rotation is recommended.
Source 2 Domestic Flamability Rated Source 2 for Low Hazard, General Domestic use
Made In the U.K. This product is made in Britain