Well i know sand has impact and all but what about this is it good does it actually work.
http://www.zoomed.com/db/products/EntryDetail.php?EntryID=188&DatabaseID=2&SearchID=1&SearchContext=YTo3OntzOjg6IlNlYXJjaElEIjtzOjE6IjEiO3M6MTA6IkRhdGFiYXNlSUQiO3M6MToiMiI7czo3OiJLZXl3b3JkIjtzOjE1OiJDYWdlIFN1YnN0cmF0ZXMiO3M6MTU6IlByb2R1Y3RDYXRlZ29yeSI7czoxNToiQ2FnZSBTdWJzdHJhdGVzIjtzOjc6IkhlYWRpbmciO3M6OToiVGVycmFyaXVtIjtzOjg6IlNlYXJjaF94IjtzOjE6IjAiO3M6ODoiU2VhcmNoX3kiO3M6MToiMCI7fQ==
http://www.zoomed.com/db/products/EntryDetail.php?EntryID=188&DatabaseID=2&SearchID=1&SearchContext=YTo3OntzOjg6IlNlYXJjaElEIjtzOjE6IjEiO3M6MTA6IkRhdGFiYXNlSUQiO3M6MToiMiI7czo3OiJLZXl3b3JkIjtzOjE1OiJDYWdlIFN1YnN0cmF0ZXMiO3M6MTU6IlByb2R1Y3RDYXRlZ29yeSI7czoxNToiQ2FnZSBTdWJzdHJhdGVzIjtzOjc6IkhlYWRpbmciO3M6OToiVGVycmFyaXVtIjtzOjg6IlNlYXJjaF94IjtzOjE6IjAiO3M6ODoiU2VhcmNoX3kiO3M6MToiMCI7fQ==