Flying a wingsuit adds considerable complexity to a skydive. The United States Parachute Association (USPA) requires in the Skydivers Information Manual that any jumper flying a wingsuit for the first time have a minimum of 200 freefall skydives, made within the past 18 months, and receive one-on-one instruction from an experienced wing suit jumper, or 500 jumps experience to go without an instructor.[20] Requirements in other nations are similar. Wingsuit manufacturers offer training courses and certify instructors, and also impose minimum jump number requirements in order to purchase a wingsuit.[21]