Safety: MSA Workman Reusable Roof Anchor
Perfect for flat or sloped roofs. 
Whether your roof is flat or sloped, the Workman Reusable Roof Anchor is the perfect fit.
It meets ANSI Z359.1-2007, and has center holes that are offset to reduce the possibility of the truss splitting during installation.
The anchor can be used on the roof peak, or off of it in a flat position without compromising strength, and attaches with either screws or nails.