resold for as much as $1100 USD upon delivery. North American Arms Mini-Revolvers (often called derringers) are 5-shot, .22 rimfire, single action revolvers, which have a spur trigger design. They are reminiscent of late 19th-century pocket revolvers, only much smaller and made completely of stainless steel. Mini-revolvers were developed by Freedom Arms in 1978, which stopped selling them in 1990 and then sold the design to North American Arms. Since then, North American Arms has further evolved the design, switching to a safety cylinder design, featuring notches machined halfway between the chambers. As a result, the revolver may be safely carried with all five chambers loaded by resting the hammer in a safety notch. Older NAA mini-revolvers can be retrofitted with this safety cylinder design upgrade at no cost to the owner simply by returning an older design NAA mini-revolver to North American Arms for an upgrade. More recently, modern pistols with polymer frames have been introduced, such as the 8-shot, .32 ACP Kel-Tec P-32 and 9 mm Luger Kel-Tec P11. The P-11 uses an aluminum receiver inside a polymer grip housing held on with polymer pins. The slide, barrel, and magazine are steel. The standard magazine holds 10 rounds, or 12 rounds in states not limited to 10-round magazines. Both fit flush to the bottom of the pistol. At unloaded, the handgun itself is comparatively light. The P-11 lacks an external manual safety, relying instead on a long and heavy double-action only (DAO) trigger pull, which requires 9 pounds of pressure, to prevent accidental discharge. A firing pin spring and low-mass hammer prevent discharge if the gun is dropped. The P-11 will also accept some Smith & Wesson 59 series magazines. An available adapter wraps around the base of 15-round Smith & Wesson model 59-style magazines. The lightweight P11s introduced the "subcompact" concept. Prompting other manufacturers such as Glock and Springfield Armory to introduce similar pistols. The Glock 26 is a 9×19mm "subcompact" variant designed for concealed carry and was introduced in 1995, mainly for the civilian market. It features a smaller frame compared to the Glock 19, with a pistol grip that supports only two fingers, a shorter barrel and slide, and a double-stack magazine with a standard capacity of 10 rounds. A factory magazine with a +2 extension gives a capacity of 12 rounds. In addition, factory magazines from the Glock 17, Glock 18, and Glock 19,