Designed for aerated concrete and aerated concrete blocks. Removable, nylon construction, corrosion-proof and able to withstand extreme loads. 18mm external spiral thread cuts into a 14mm drilled hole and ensures a tension-free fastening ensuring no expanding and cracking. Simple and quick to install with a hex key. Compatible with 10mm metric and 3/8 inch imperial screws Nylon Construction Suitable For Aerated Concrete Blocks Aggressive Coarse Thread Improves Pull-Out Strength Suitable For All Types of Screws Simple & Quick to Install with Hex Key Nylon Construction Suitable For Aerated Concrete Blocks Aggressive Coarse Thread Improves Pull-Out Strength Suitable For All Types of Screws Simple & Quick to Install with Hex Key