摘要 |
<p>The bolster (a) has a burring device (b) including a foil provided at a vibration device, where the bolster has different thicknesses and is made of soft material such as foam rubber, plastic, natural sponge, artificial sponge, textile or wool. A washable, elastic cover is provided, where the bolster is designed as a hollow body and in the form of square, circular, triangular, polygonal and oval, with rounded corners.</p> |