One of the features of our GRProto reels is that the two frame sizes have interchangeable spools. We designed them this way in order to offer a better value on a fly reel. The A-Frame can either be paired with the 4+ spool or the 6+ spool, and the B-Frame can be paired with either the 8+ or 10+ spools. Buy spools in different sizes in order to pair the same reel with a range of rods. The B-Frame loaded with the 8+ spool will balance your 7 wt. streamer rod perfectly, and is quickly swapped with the 10+ spool to be thrown on your heavy spey rod or big game salt water rod. Do the same with your A-Frame reel and pair it up with both your 4 wt. and your 6 wt. rods. Keep in mind that the drag system is easily configurable in order to match the species you are targeting. Spool Only! Photos are to illustrate size and color combos only.