The Sellita SW215 is the main competitor to ETA‘s caliber 2804-2, but with an additional 2 jewels.
According to Sellita it takes a minimum of 23 turns to of the crown to wind this movement. The average rate should be within +/- 12 seconds/day. There is another variation of this caliber that Sellita designates as “Special” and is said the keep time within +/- 7 secs/day.
Many reputable watch companies are using this movement as an alternative to the ETA mechanism due to it being more economical and readily available. You may have seen this movement written as the SW-215 but according to Sellita, the correct way to spell this caliber number is SW215 without a hyphen.
We still need a live shot of this movement in a real watch. Please submit one to complete this post.