Escon Heavy duty Wedge belts contain high modulus polyester cords , which together with specially formulated bottom compression rubber compound and insulation rubber , constitute over unshakable union even under severest flexing conditions . Escon Wedge belts do not buckle even on the toughest segments and are most preferred in most compact industrial drives. Escon Wedge belts confirm to IS 14261 and BS 3790 Wedge belts manufactured by ESCON are SPZ, SPA, SPB, SPC, 3V, 5V and 8V