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.
20 mm
Verification: From our database, not yet verified
40 mm case
Indicative information. Check your watch before buying a strap: whatsmylugwidth.com is not responsible for an incorrect size.
The Isotope Old Radium Bronze takes a 20 mm strap: all 7 references with a listed width in our database use 20 mm. Check the reference on your case back to be sure.
Isotope Old Radium Bronze 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: 20 mm
Source: DatabaseCase size: 40 mmBlack enamel dialCase material: CuSn8 bronze, titanium caseback
Lug width: 20 mm
Source: DatabaseCase size: 40 mmAsh Grey (textured) dialCase material: CuSn8 bronze, titanium caseback
Lug width: 20 mm
Source: DatabaseCase size: 40 mmOlive Green (textured) dialCase material: CuSn8 bronze, titanium caseback
Lug width: 20 mm
Source: DatabaseCase size: 40 mmOx Blood Red (textured) dialCase material: CuSn8 bronze, titanium caseback
Lug width: 20 mm
Source: DatabaseCase size: 40 mmTobacco brown textured dialCase material: CuSn8 bronze, titanium caseback
Lug width: 20 mm
Source: DatabaseCase size: 40 mmWhite enamel dialCase material: CuSn8 bronze, titanium caseback
Lug width: 20 mm
Source: DatabaseCase size: 40 mmWhite Milk enamel dialCase material: CuSn8 bronze, titanium caseback
No reference matches.
The Isotope Old Radium Bronze takes a 20 mm strap: all 7 references with a listed width in our database use 20 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 7 Isotope Old Radium Bronze references, 7 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.