There are three sizes.
1# specification
Full length 27.5CM
Blade entry width 4.3cm
16 cm long blade can be placed
Handle length 10.7cm
Suitable for 3.5-5mm thick knife
2# specification
Full length 26CM
Blade entrance width 4.0cm
14cm blade length can be placed
Handle length 10.7cm
Suitable for 3.5-4.7mm thick knife
3# specification
Full length 23CM
Blade inlet width 4cm
The blade length of 12cm can be placed
Handle length 10.7cm
Suitable for knife with thickness of 3.5-4.5mm