The material generally used for cylinder sleeves is

resistance to wear

the characteristic that is enhanced by the use of cylinder sleeves is resistance to wear.

honing

The reconditioning process used to give cylinder bore surfaces a cross hatch pattern, is known as honing.

lubrication performance

Lubrication performance is enhanced by honing of cylinder sleeves inner surface.

smaller engine dimensions

The main merit of a multi cylinder type cylinder sleeve is smaller engine dimensions.