Dynam main gear electric retracts, 2 main gear with wheels included, plus a spare retract .as well. These do not swivel so cannot be used for 3 gear retracts.for up to 3 lb planes 25 size or so. Work real good just (y ) them together. Plug into spare ch on your rx. All three sell for 17.00 shipping is free in the U.S. only. PayPal or mo accepted.