The TEKTO F4 Echo is a manually operated folding knife developed in collaboration with Zastava Arms USA for everyday carry, outdoor tasks, and general utility cutting. Its styling draws inspiration from classic Zastava rifle components, pairing a black aluminum handle with Serbian Red G10 inlays and elongated vent-like cutouts. This construction gives the knife a distinctive profile while maintaining a practical 2.64-ounce carry weight. The fine-edge reverse tanto blade measures 3.40 inches and uses S35VN steel hardened to 60-62 HRC. A black titanium coating provides a deep matte appearance and adds another layer of corrosion resistance to the blade surface. The reverse tanto geometry combines a defined point with a long, usable cutting edge for opening packages, trimming cord, preparing gear, and handling other controlled cutting jobs encountered during daily use or time outdoors. The F4 Echo is a true manual folder rather than an automatic knife. Its blade deploys through the flipper tab, while the button-lock mechanism provides secure lockup and allows controlled disengagement without requiring the user to place a finger directly in the blade's closing path. At 7.70 inches open, with a 4.30-inch handle and a slim 0.5-inch handle width, this configuration offers useful reach without becoming unnecessarily bulky in a pocket. An ambidextrous pocket clip supports convenient carry from either side, and the integrated lanyard hole provides another retention or carry option. TEKTO also supplies a fitted pouch for storage and transport. Combining premium blade steel, lightweight aluminum and G10 handle construction, deliberate manual operation, and a compact carry profile, this Serbian Red version of the F4 Echo is suited to users who want a capable folding knife with recognizable collaboration styling and practical everyday dimensions.Specifications and Features: 3.40-inch fine-edge reverse tanto blade Titanium-coated S35VN blade steel 60-62 HRC blade hardness Black aluminum handle with Serbian Red G10 inlays Manual flipper deployment with button lock 7.70-inch overall length; 4.30-inch handle Ambidextrous pocket clip and lanyard hole Tekto pouch included Product Weight: 2.64 ounces Brand: TEKTO Series: F4 Echo Product Type: Manual Folding Knife Manufacturer Part Number: F4R_T6GRD_S35BK5_A1 UPC: 850034486178