Features: The knockout seal serve as a reliable addition to your toolbox, making them ideal for both electricians and DIY enthusiasts. Our electrical box knockout plugs are easy to install and can be quickly inserted into tapping hole without the need for special tools or equipments. Specifications: Material: steel Color: gray Size: as pictures show Package includes: 36 x Knockout seals Notes: Manual measurement, please allow slight errors on size. The color may exist a slight difference due to different screen displays. The product size is small, adults should supervise, children may have the risk of accidental ingestion and suffocation.