noun which may take the genitive case particle 'no'
half-size
Describes something that is half the usual size, often used for clothing, portions, or equipment.
このドレスはハーフサイズで作られています。
This dress is made in a half-size.
ハーフサイズのギターは子供にぴったりだ。
A half-size guitar is perfect for children.
Borrowed from English 'half-size'.