These pieces of neoprene were part of the emergency/survival rucksack #1 that was flown on the Apollo 15 mission in July/August 1971. They were included as protectors and would have been used to protect the astronaut's hands while pulling fishing line for example, or as padding for equipment.
This item was transferred from NASA to the Smithsonian in 1978.
This object is on display in Human Spaceflight at the Steven F. Udvar-Hazy Center in Chantilly, VA.