Sinn Model 144 St Sa

The Sinn Model 144 St Sa is a pilot chronograph which comes in a 41 mm x 14.5 mm stainless steel case with a bead-blasted matte finish. It features a sapphire crystal in front and back (both with an interior anti-reflective treatment). The case back is secured with screws and the crown screws down. Water-resistance is 200 meters.
Powering the Model 144 is a reliable Swiss made Valjoux 7750 which features 25 jewels, a stop second function with a rate of 28,800 vph (4Hz). It is shock resistant and anti-magnetic. Functions include hours, minutes, subsidiary seconds, date, day of week and chronograph with tachymeter and pulsometer scales.