The mechanisms of the SUNDIY system are securely fixed to the structure (whether wood, aluminum, concrete, etc.) using the fixing clips, which must be pre-screwed. The screws provided here are specially designed to ensure an effective fixation in CONCRETE.*
As for calculating the number of screws required, it is recommended to plan for 4 to 6 screws per pair of mechanisms.
The CLIPS are INCLUDED with the SUNDIY mechanisms.