This shallow spool has SV Boost brake specifically tuned to be used with PE braided lines of thinner than #0.8. It Flat bottom, ultra light-weight 11g spool to improve casting performance. Made of G1 grade duralumin. In the SV-Boost brake, rotor will pop out far only at the beginning of casting to prevent backlash, and then it retracts to the middle to reduce brake to add casting distance. The second half spring is 4 times stronger than first half to do the trick. Casts great for heavier than 3g 1/8oz. PE0.8-150m, 0.285mm(US10lb)-70m(80yds)