extra large mag float... really? $134.99?

I noticed that I'm getting some algae buildup on my acrylic tank already, so Idecide to search what ways are safe to clean it before I do anything stupid. Lead me to Dr. Foster's site where I find mag floats specific to acrylic (good thing I didn't use my existing one, I guess). So Iskim the prices and think ok, ok, whoa, OMG!

For $135 is the extra large the size of a VW bug? What gives?