Cast brass and white porcelain wheel castor. This item is made in India to a high standard and is also available with a brown porcelain wheel. IS25W is virtually identical to ES25 also listed in this group. The major difference is the price.
IS25W
Brass White Porcelain
a=25 b=37
$8.65
IS32W
Brass White Porcelain
a=32 b=42mm
$10.50
IS38W
Brass White Porcelain
a=38 b=48mm
$15.30
$ Australian
Other suggestions:
ES25
653
VR653