Sorry it took so long....I was building one of my Provari's
That is a Bippee lab design [Burmingham AL] and they are labeled with many names.
This is an SH-2 which has 2x magnet strength of the SHC-1 MSUK
Either one will work fine. The difference is the magnets basically, and they do lose strength over time.....even though you may never even notice unless you mix large volumes.
Between the two, I would buy the SH-2 because it is a step above the SHC-! and will probably perform forever, although both may do so.
Basically, the larger the model number-the better/stronger the magnet, and that is almost the only part that weakens over time. SH-1 vs SH-2 vs SH-3 [or SHC-1 vs SHC-2] etc. etc.