There are many different kinds of replacement doors.  We use only lifetime warrantied fiberglass and vinyl doors that come pre-hung on lifetime warrantied vinyl jambs. Any door glass come standard as low-E insulated glass. We provide to our customers four door manufacturers. These manufacturers are Plastpro and Therma-Tru for fiberglass doors and Alside and PGT for vinyl doors. Between these manufacturers we have a very large selection of designs sizes and decorative options available. We use Plastpro made by Builders Hardware Inc in Tampa for about 90% of our residential replacement jobs. Below I've listed all of the manufacturers and a link to their website.