This is the fee to install bearings onto spools. This service is only for customers who purchase bearing and spool together. Bearings on short shaft model, like Daiwa, Revo (except Gen 1 S and ST) requires to use pin remover, and this service is to do it for you. For long spool shaft reels like Shimanos, you don't have to replace the bearing on the shaft because it is not related to casting performances. It is to support shaft in case very large load is applied. For those reels please replace the two bearings at the both ends of spool shafts.