unika started to sell set Non-Plug screw (screw dia M4) and concrete drill bit B type.

M4 Non-plug Screw has 9 kinds and the set has 2 kinds (Set A and Set B).

• Set A: If the material to use Non-Plug screw is "Concrete" or "Block", please choice Set A (1 kind of Non-Plug Screw 1 box + drill bit B type 3.5φ 1 pcs)
• Set B: If the material to use Non-Plug screw is "Brick", please choice Set B (1 kind of Non-Plug Screw 1 box + drill bit B type 3.2φ 1 pcs)

	More information please see here.

Page "Non-Plug Screw"		Page "drill bit B type"