Two-Screw Clamp: For 1913 style Picatinny rails only. It requires a flathead (or anything that will fit into the slots of a flathead) for installation and removal. Because installation and removal is not timely, the two-screw clamp is suggested to be more of a permanent mounting solution to a rifle you know you want to dedicate that bipod to (ie: a hunting rifle). The positives of this option are a decrease in apex height, weight, bulk and price otherwise associated with an installed quick detach lever.
No Clamp (NC): Sent without a clamp or means to readily attach to any rail system. It has a two hole pattern of 1.100” with 10/32 threads. Requires any 17S size lever style mount (ie: LT271 from LaRue Tactical, Picatinny Rail Slider from Arisaka or ARCA mount) with the same hole pattern. This is also for application specific solutions to mount directly to our BT19 AI Spigot and BT70 M-LOK® Adapter. This is a great option if you already have your own 17S size lever. Two 10-32 x 3/8” flathead socket screws are included. Designated in model number by “NC”
Quick Detach Lever (LW17): For 1913 style Picatinny rails only. This provides a means to quickly attach and detach an Atlas Bipod by using the installed ADM-170-S, which is manufactured by American Defense Manufacturing. Adjustment to fit to the 1913 style Picatinny rail does not require tools and accommodates for both in spec and out of spec rail systems. This is a great option if you are planning to use one bipod on multiple firearms outfitted with a 1913 style Picatinny rail. Designated in model number by “LW17”
If none of these are a definitive solution for attachment to your rifle, you may need to install a rail or adapter. Here is our Atlas Bipod Rail Comparison Chart with options and specifications including general purpose, Anshutz, Freeland, Free float tube, M-LOK®, etc.