The T4'21 Aluminium Extra Flex 2.0mm Swiss 7075 T6 produced by XRAY, is classified in
Aluminum T4'21 framework with unique cutout openings for increased flex. This chassis is preferred for low traction carpeting songs and high traction asphalt songs. (not advised for high- and very-high carpet traction songs where either the #301005 or #301006 framework work better). Fits T4'21