Every reference with a known width takes the same strap size. Your reference is engraved on the case back or between the lugs at 6 o'clock.
19 mm
Verification: From our database, not yet verified
38 mm case · 1953 to 1958
Indicative information. Check your watch before buying a strap: whatsmylugwidth.com is not responsible for an incorrect size.
The Longines Chronograph 30CH takes a 19 mm strap: all 5 references with a listed width in our database use 19 mm. Check the reference on your case back to be sure.
Longines Chronograph 30CH references in our database. Each card says where its width comes from: listed by the maker (linked to the maker's page in the details), two independent sources agree, or listed in our database and not yet verified by us.
Lug width: 19 mm
Source: DatabaseCase size: 38 mmYear: 1957Silver dialCase material: Steel
Lug width: 19 mm
Source: DatabaseCase size: 38 mmYear: 1958Silver dialCase material: Steel
Lug width: 19 mm
Source: DatabaseCase size: 38 mmYear: 1953Black dialCase material: Steel
Lug width: 19 mm
Source: DatabaseCase size: 38 mmYear: 1955Silver dialCase material: Steel
Lug width: 19 mm
Source: DatabaseCase size: 38 mmYear: 1956Silver dialCase material: Rose Gold
No reference matches.
The Longines Chronograph 30CH takes a 19 mm strap: all 5 references with a listed width in our database use 19 mm. Check the reference on your case back to be sure. These widths come from our database and are not yet verified.
From our database, which lists 5 Longines Chronograph 30CH references, 5 of them with a listed width. Each reference card says whether the maker lists the width, two independent sources agree on it, or it is not yet verified.
The gap between the two lugs that hold the strap, in millimetres. A new strap must match it exactly: 20 mm lugs take a 20 mm strap.
Most watches use spring bars, so any strap of the right width fits. Many smartwatches use their own band system instead, such as Apple Watch bands or Garmin QuickFit.