Two designs are included in this download. The Super and the Basic designs.
Both designs are compatible with a standard LR-308 lower build kit.
The Super Lower requires the reinforcement kit available at hoffmantactical.com. 
The Basic Lower requires a size 28 hose clamp and two 10-32 x 1.25” bolts and nuts. You will need to tap the pistol grip bolt hole with a ¼ -20 tap. The front take down pin plates are printed separately from the lower, and attached with the bolts.
We recommend PLA, PC, or PETG for the main body of the lower. And PC or PLA for the front takedown pins.
It is recommended to tune your print settings using the Lower Test Print before printing a complete lower. The 3MF file contains the reccomended print settings.
See hoffmantactical.com for more info.
Happy Printing!