Prince kevlar hybrid with synthetic gut duraflex 1.30mm, for durability and control. One of the most durable strings on the market. Suitable for string breakers, has a stiff feel for control. Prince kevlar manufactured by Du Pont, USA is the only genuine kevlar on the market. Kevlar is a very tough material which is used for protection from bullets fire. To cut kevlar you need clippers with hardened steel jaws, for example Maun made in UK; standard clippers will not cut kevlar.