耐久性优越，在封闭式中是通用的类型。大型尺寸能够进行多层分隔。
| 形式 | 内高 | 内宽 | 弯曲半径 |
| TKC28H30 | 30 | 28, 48 | 67, 100, 125 |
| TKC34H25 | 25 | 50, 90, 130 | 70, 100, 150 |
| TKC47H36 | 36 | 80, 160 | 100, 150, 200, 250 |
| TKC64H50 | 50 | 110, 220 | 135, 200, 250, 300 |
| TKC91H56 | 56 | 150, 200, 250, 300, 350, 400 | 200, 250, 300, 350, 400 |
| TKC85H68 | 68 | 150, 200, 300, 350 | 180, 250, 350 |
| TKC91H80 | 80 | 150, 200, 250, 300, 350, 400 | 200, 250, 300, 350, 400, 450, 500 |
