A) single tube Corebarrel
Size : 56mm , 59 mm, 75 mm , etc
B) Double Tube Corebarrel : different parts of double tube corebarrels are as follows:
1) head
2) Extension Tube
3) Corelifter case
4) Corelifter
5) Outer tube
6) Inner tubeSize : 1.5 m  - 3 m