rice husk mobile cases are new to the world market but are a great novalty product to have as a personal item. the cases are made from reclycled plastic and bio waste rice husk. they come in various colours black white grey green purple clear ( you can see the husk inside ) as most mobile phones have a type of electro magnetic wave that can interfere with other electro waves the shield is there to cancel any interference between multiple electro wave paths. it is provided as all our mobile phone cases come with a slot for a card (i.e.: rfid card, credit card, metro card, etc), which also has a electro wave. without the em shield, the card would have very limited sensitivity when placed in the iphone case with the iphone.