Factory Spec severe duty brake pads are made of a sintered bronze compound. Their exclusive high-density mix extends pad life for use in extreme conditions such as sand, mud, water and farm usage. If long life is your main concern, these brake pads are your best choice. They will last much longer than any semi-metallic or organic brake pad on the market. Manufactured by Factory Spec Included is two sets of brake pads, as pictured This is enough to replace the pads on the front calipers Made in China These sintered metal brake pads fit the following models 2003 Polaris Trail Boss 330 2004 Polaris Trail Boss 330 2005 Polaris Trail Boss 330 2006 Polaris Trail Boss 330 2007 Polaris Trail Boss 330 2008 Polaris Trail Boss 330 2009 Polaris Trail Boss 330 2010 Polaris Trail Boss 330 2011 Polaris Trail Boss 330 2012 Polaris Trail Boss 330 2013 Polaris Trail Boss 330