| Type | Brass Block Size | Base Material | Terminals & Screws | Available Size | Remarks |
| Plug Key | 9 mm | Heavy Bakelite | All Brass | 1-Way, 2-Way, 3-Way | Compact design, suitable for general lab use and basic experiments. |
| Plug Key | 10.5 mm | Heavy Bakelite | All Brass | 1-Way, 2-Way, 3-Way | Thicker brass block for better conductivity and durability. |
| Plug Key | 12 mm | Heavy Bakelite | All Brass | 1-Way, 2-Way, 3-Way | Extra-thick brass block; ideal for heavy-duty applications and higher load. |
