This is a four-piece inflight coverall garment assigned to astronaut Michael Collins for use during his Apollo 11 mission in July 1969.
The complete garment consists of jacket, which was equipped with reinforced holes on the upper torso through which the medical connectors could pass; trousers with a snap and elastic waist for adjustment; and boots which had a snap attachment to the legs of the trousers and a circular Velcro patch on the soles. It is constructed of a Teflon-coated beta cloth which is highly fire resistant, and the "slippery" qualities of the fabric enabled the astronaut to don and doff the garment with ease in a weightless environment.
NASA transferred these trousers to the Museum in 1974.
This object is on display in Destination Moon at the National Air and Space Museum in Washington, DC.