OK; I was hoping to hear from the seller. Assuming the "FS" meant "For Sale" and he just left of the "-1" or "PL" designation which would designate the gear as a vertical offset. I've got two of these in my DMR, but they are 2.5 to 1. Wondering what it would cost to change the ratio in one. THey can be remarkably hard to find compared to the down angle version, which would be a 280-A instead of a 280-1 or 280-PL.