This spool extends casting distance by reducing brake force at the later half in casting. Fits to Daiwa 1000, 1012, 1025 and 1016 reels, T3(all models) and etc. Flat bottom, ultra light-weight 11g spool to improve casting performance especially for ultra light weight rigs 3g-7g 1/8-1/4oz. G1 grade duralumin. In 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. 0.330mm(US12lb)-80m(90yds)