These masts are all about value and durability. The epoxy composite construction will stand up to the abuse of school use and offers the first timer a super durable affordable mast. 100% Epoxy Construction Two piece mast SDM/Standard diameter SizeDiameterCarbonWeight 310 SDM 0% 3.25lbs 340 SDM 0% 4.3lbs 370 SDM 0% 4.7lbs 400 SDM 0% 4.95lbs 430 SDM 0% 5.75lbs 460 SDM 0% 5.9lbs