In the early 1942, the Panzerkampfwagen II (Sd.Kfz.121) light tank was withdrawn from frontline Panzer units and relocated to second line duties after being in service since 1936. That step provided the opportunity to use its reliable chassis and components for conversions such as the Marder II tank destroyer and Wespe. Alkett designed the Wespe in mid 1942, and its practical design was chosen over other designs based upon the Panzerkampfwagen III or Panzerkampfwagen IV’s chassis. Wespe (Wasp) was a light self-propelled gun armed with a 105mm light field-howitzer and based on the unmodified and modified Panzerkampfwagen II Ausf F chassis. Wespe received the designation Sd.Kfz.124, but was also known as the 10.5cm le FH18/2 Fahrgestell auf Geschützwagen PzKpfw II and as the Leichte Feldhaubitze 18/2 auf Fahrgestell PzKpfw II (Sf).
The main idea behind the design of Wespe was to provide all mobile formations with proper and indirect artillery support. Wespes were to operate behind the frontlines and were not to engage enemy vehicles, however, they carried armor-piercing ammunition in case of an encounter. Like artillery, the Wespe operated in batteries and received orders and directions from forward observers by radio or field telephone: reducing the risk of being exposed to direct enemy fire.
The Wespe was based on the regular Panzerkampfwagen II Ausf F light tank chassis and on modified Panzerkampfwagen II Ausf F chassis'. Both versions used many standard components of the Panzerkampfwagen II Ausf F light tank. Ausf F was the last variant of Panzerkampfwagen II to enter full-scale production. Ausf F was produced by FAMO of Breslau (Wroclaw) and some 1400 chassis were manufactured, while 524 were completed as tanks from 1941 to 1943. This model featured increased armor protection and other modifications based on battle experience.
The early version of the Wespe was based on a regular tank chassis with engine moved forward (to a more central location) and the suspension reinforced in order to absorb the stress from firing-recoil. The later version was based on a modified chassis with a slightly lengthened (by 220mm) hull, engine and radiators moved forward (to more central location), and the suspension reinforced to absorb the stress from firing-recoil. The longer hull resulted in an increase in the space between the last road-wheel and idler. Modified chassis' were known as Geschützwagen II - Gun Vehicle / Gun Carriage IIs. The configuration of the driver compartment was changed during production, creating two variants as well.