ESP Syncro XT 1000m

The XT of Syncro literally stands for extra tough, indicating that this exceptional monofilament is highly abrasion resistant and durable. 

The breaking strain quoted on each spool is an easily achievable knot strength, appropriate to its diameter. However, with carefully tied, mechanically superior knots like the five turn grinner, average breaking strains can be significantly increased as indicated below. 

15lb (possible 21lb), diameter 0.37mm 
18lb (possible 26lb), diameter 0.40mm