The SdKfz 251/21, also known as the Mittlerer Schutzenpanzerwagen Drilling MG 151, was a very effective production anti-aircraft version of the SdKfz 251 halftrack. Mounted with three excellent 15mm MG 151/15 or 20mm MG 151/20 machine guns on a compact pedestal behind a small armored shield, having a rate of 700 rounds per minute per gun, these modified SdKfz 251 halftracks could provide very effective defensive fire against the Allied aircraft.Newly tooled parts include conical pedestal mount, MG151 with detailed cradle, one-piece slide-molded 3-side armor, ammo bins and ammo belt with nice details, additional upper superstructure armor, new armor plate for drivers roof, stowage box and spare ammo bins, and gunner. Special features include brass flash suppressor for the barrel, rotating and elevating MG, tools stowage box with option to open/close, clear vision blocks with interior and open/close option, innovative ez-track," extra regular individual track links, front seat with photo-etched seat back spring, slide-molded rear tow shackle, road wheels details-up with engraving, and details-up in both side of lower hull with photo-etched parts. Bonus features include soft vinyl true-scale uniforms, brass width indicator bars, brass ammo, brass spent shell casing, bonus driver, and four anti-aircraft crew. Also includes Cartograf decal sheets for various markings and silver stickers for side mirrors.