The UTG PRO AR-15 Ops Ready S4 Mil-Spec Stock (brand part no. RBUS4BMS) is molded from impact-resistant, high-strength matte black polymer, built with the same 4.28-inch, 4-position adjustable body as UTG’s S4 stock kit but sold here as the stock alone. That adjustability gives a comfortable length of pull and easier shouldering while wearing a load-bearing vest or plate carrier system. It includes a slanted cheek rest along with a removable 5.51-inch extended cheek rest insert for a higher, more consistent cheek weld with taller optics, plus a rubberized butt pad and a reversible sling swivel housing with a standard sling loop.

Key Specifications

• Molded from impact-resistant, high-strength matte black polymer.
• Stock body measures 4.28 inches with 4-position adjustability.
• Includes a slanted cheek rest and a removable 5.51-inch extended cheek rest insert.
• Rubberized butt pad for shoulder comfort.
• Reversible sling swivel housing with a standard sling loop.
• Built for heavy-duty use with tight tolerance controls.

Frequently Asked Questions

What is the extended cheek rest insert for? It’s a removable 5.51-inch piece that raises the cheek weld for a more consistent sight picture with taller optics.

How many positions does the stock adjust to? Four positions across a 4.28-inch body.

Buy the UTG PRO AR-15 Ops Ready S4 Mil-Spec Stock, Black

Get a comfortable, adjustable stock ready for load-bearing gear. Order the Leapers UTG stock from our AR braces and stocks selection at our Lubbock, Texas gun shop for fast, direct shipping.