BC is base curve. I beleive valves are 8.75 which is pretty common. Stay away from 7.25 BC or Toric BC.UUhhhh. Hate to say this guys. But the O-bbreviation list didn't have BC, SL, or NSJ2. Still need help with those please.
SL is straightlink...a very common donor often found for around $25 to $35.
NSJ2 is New Straight Jecket 2. I wouldn’t use these lenses as donors as that is a discontinued frame and lenses are harder to come by...