The inner diameter of brushes is the standard size of 1.25 inch/ 32 mm. Vacuum Adapter Kit converts 1 3/8-inh to 1 1/4-inch, it help vacuum cleaners with 35mm outer diameter of vacuum hose or wand can use 1-1/4 inch (32mm) vacuum accessories. Please mearsure dimension of your vacuum hose or wand before purchasing.. you receive 5 pieces vacuum cleaner attachment replacements, with 3 pieces 25 mm round dust brushes and two 1-3/8 to 1-1/4 inch hose adapters. The inner diameter is the standard size of 1.25 inch/ 32 mm The horsehair brushes are super soft so you can use it anywhere and don't worry about scratching the . Vacuum Attachment Adapter Kit: Convert from 35mm (1 3/8-Inch) to 32mm (1 1/4-Inch), it help this brush can be compatible with for and more vacuum cleaners with 35mm outer diameter of vacuum hose or wand. Please check dimension of your vacuum cleaner hose or wand before ordering. Material: plastic colour: Black Package Contents: 3 x Brush head 2 x Adapter head Only the above