Weaver Top Mount Base 401S is engineered for Smith & Wesson L, K, and N Frame platforms. Constructed from durable aluminum in a silver finish, this base utilizes a Weaver rail interface standard for scope and accessory attachment. It includes dedicated mounting hardware for direct firearm mounting without rings included. Safety Note Always ensure the firearm is unloaded before installing or adjusting any optics or bases. Verify proper torque specifications during installation. Improper mounting may affect accuracy and safety.