The frame is made from polymer, a strong and lightweight plastic, whilst the slide is made from a an aluminium and zinc alloy. The Mosquito, thanks to these factors, only weighs 24.6oz.
The majority of the internal mechanics are taken from the full sized P226, the exceptions being a takedown lever and decocking lever located on the left side and a reversible magazine catch.
Safety is controlled through several controls, the central one being an ambidextrous manual safety, located behind the slide. A seperate integral safety lock (which prevents the slide cycle, hammer drop and trigger action) is located behind the magazine .
An accessory rail is fitted as standard.
The SIG Mosquito is sold with an accessory rail as standard. Hence SIG Sauer sell mount lasers and lights for the Mosquito, as well as extra magazines and holsters. Another add-on avaliable from SIG Sauer is the polymer bridgemount allowing the Mosquito to be equipped with a red dot sight or scope, replacing the adjustable sights fitted as standard.
The Mosquito is only avaliable chambered in .22 LR, shot from a 10 round magazine.
The Mosquito is sold on various guises. These are:
- Mosquito (standard)
- Mosquito Sport - 4.9in barrel, additional weight for increased accuracy
- Mosquito TB (Threaded Barrel) - Barrel accepts a suppressor
- Mosquito Two-Tone - Stainless steel slide / black frame
- Mosquito Reversed Two-Tone - Black slide / Stainless steel finished polymer frame
- Mosquito FDE (Flat Dark Earth) - FDE frame and slide, polymer grips
Special editions are sold finished in:
- Desert digital camoflage
- Winter digital camoflage
The SIG Mosquito is sold by SIG Sauer as "Scratching the itch", the 'itch' referring to target shooting. The Mosquito receives some criticism for the trigger system, described as "gosh awful" by one user on the website Bass Pro Shops. However the Mosquito has received wide and overwhelming praise for its ease of use, quality and, most importantly in many respects, value for money.