Many of the surgical techniques proposed over the years for inguinal hernia repair have been associated with a high number of recurrences due to the presence of great tension on the suture line and to a lack of consideration for the alteration of the collagen metabolism at the fascia trasversalis level. The advent of the new "tension-free" techniques, among which that described by Trabucco, has represented a turning point in inguinal hernia surgery. In this article, the characteristics, indications and use of the T4r "flat mesh" in this hernioplasty are described. The T4r is not a real "plug" but a "flat mesh", a 5 cm-diameter-round pre-shaped polypropylene mesh with an intermediate rigidity grade with a 1 cm diameter hole in an eccentric position for the passage of the elements of the spermatic funicle. To make its collocation inside the deep inguinal ring in the preperitoneal position easier, a Foley catheter (14 Ch) is used whose balloon is inflated with 20-30 cc of physiologic solution or air. One of the actual problems among the possible complications of prosthetic surgery of hernia is the "migration" of the plug and thus the use of "plugs" in the Trabucco inguinal hernioplasty has been reconsidered. The positioning of the T4r in place of a three-dimensional plug like T1 in particular is an elective choice to prevent the risk of compression of the loco-regional vascular structures.