There are a number of different typres of mattress which can be quite confusing.  Here is a brief explanation of the various types.  It does make a big difference to the quality of the mattress, how long it will last and of course... to the price.
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Open Coil
The separate springs are arranged in rows and connected to one another by a spiral wire. An outer rod strengthens the edges of the mattress. Some higher quality beds will use a continual  spring system, made from one piece of wire shaped into a series of springs. This is a cost effective and popular choice offering good support.  
                  
Pocket Sprung 
Each spring is housed within it's own individual fabric pocket. This enables the springs to work independently of one another, offering unique support to the body shape and helping to prevent pressue points. A Luxurious sleeping experience offering the highest levels of support.  

Memory Foam 
The 'new kid on the block'! This is a relatively new type of material that has a unique feel and responds to your body temperature and body weight to change shape.  It slowly recovers its original shape when the heat and pressure is removed.  A unique combination of support and comfort with excellent pressure relieving properties. 
                    
High Tech Latex 
A prized naturally derived material, sourced from the sap of the rubber tree.  It is a distinctive feel and is resilient, durable and has excellent anti-microbial properties that mean it's suitable for many allergy sufferers.  It has natural Elasticity and quickly recovers it''s shape allowing for great support and comfort. 
                    
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