These blocks are rectangular in shape and had more or less the same size as the bricks. During the past five decades, the block shape has steadily evolved from non-interlocking to partially interlocking to fully interlocking to multiply interlocking shapes.
- Sturdy construction
- Great strength
- Longer service life
| Colors | Red / Yellow / Gray / Black / White |
| Thickness | 60 mm |
| Compressive Strength | M 25 |
