Screwdown case back, Once set, the calendar automatically adjusts for odd and even months includuing Feburary of leap years up to 2100, Second hand can indicate month, date and number of years since last leap year, High accuracy-yearly loss/gain rate of less than 20 seconds, Battery life indicator, Bracelet has push button release clasp, Battery life of approximately 5 years. Two-Toned Stainless Steel Bracelet Brand: Seiko Style: SLL086 Size: Mens Movement: Perpetual Calendar Crystal: Hardlex Mar-Resistant Crystal Rated: 50 Meters(165 Feet) Attachment: Two-Toned Stainless Steel Bracelet