Bought my new echelon from factory with number 3 mods. Within a week switched to number 4. Putting the number 3 up for sale. On my 37 they make 30 inch draw, not real sure what draw length they make on the 39. Used for about one week still look like new. $40 TYD. PM or text (606)389-0654 for fastest response. Thanks for looking.