Siffofin wannan mold sune:

1. Ana danna rami ɗaya ta silinda ɗaya

2. Akwai garkuwar zafi a ƙarƙashin kogon mold

3. Jigon (bushi) yana zafi

4. Wannan tsarin zai iya samar da wasu nau’ikan pad ɗin birki:
faifan birki, fakitin birki na ganga, birkin jirgin kasa, birki mai sauri na dogo, birkin keke, da dai sauransu.