diff --git a/public/locales/cs/send.ftl b/public/locales/cs/send.ftl
index 3abc0191..458afce5 100644
--- a/public/locales/cs/send.ftl
+++ b/public/locales/cs/send.ftl
@@ -120,7 +120,17 @@ fileCount =
         [few] { $num } soubory
        *[other] { $num } souborů
     }
-# size is a localized number followed by a unit of bytes, ex. 2.5GB
+# byte abbreviation
+bytes = B
+# kibibyte abbreviation
+kb = KB
+# mebibyte abbreviation
+mb = MB
+# gibibyte abbreviation
+gb = GB
+# localized number and byte abbreviation. example "2.5MB"
+fileSize = { $num } { $units }
+# $size is the size of the file, displayed using the fileSize message as format (e.g. "2.5MB")
 totalSize = Celková velikost: { $size }
 # the next line after the colon contains a file name
 copyLinkDescription = Soubor můžete sdílet tímto odkazem:
@@ -154,15 +164,15 @@ uploadButton = Nahrát
 # the first part of the string 'Drag and drop files or click to send up to 1GB'
 dragAndDropFiles = Přetažením myší nebo kliknutím sem
 # the second part of the string 'Drag and drop files or click to send up to 1GB'
-# size is a localized number followed by a unit of bytes, ex. 2.5GB
+# $size is the size of the file, displayed using the fileSize message as format (e.g. "2.5MB")
 orClickWithSize = můžete poslat až { $size }
 addPassword = Chránit heslem
 emailPlaceholder = Zadejte svoji e-mailovou adresu
-# size is a localized number followed by a unit of bytes, ex. 2.5GB
+# $size is the size of the file, displayed using the fileSize message as format (e.g. "2.5MB")
 signInSizeBump = Pro odesílání souborů o velikosti až { $size } se prosím přihlaste
 signInButton = Přihlásit/Registrovat se
 accountBenefitTitle = Vytvořte si účet { -firefox(case: "gen") } nebo se přihlaste
-# size is a localized number followed by a unit of bytes, ex. 2.5GB
+# $size is the size of the file, displayed using the fileSize message as format (e.g. "2.5MB")
 accountBenefitLargeFiles = Sdílejte soubory o velikosti až { $size }
 accountBenefitDownloadCount = Sdílejte soubory s více lidmi
 accountBenefitTimeLimit =