1Gutter hangers come with pre-inserted 3inch long, 1/4 inch hex head self piercing screw, you can easily Install them with 1/4 inch nut driver and cordless drill. Gutter brackets should always be placed at least every three feet for proper support (2 feet in northern climates where snow and ice can add additional weight on the gutters). Our gutter brackets are heavy-duty brackets made of aluminum alloy with reinforcing rods and galvanized screws. These hangers are designed to , and to breakage, providing secure support for your gutters. These hidden gutter hangers feature superior engineering. Screw fixing grooves - threads engage well and reduce slippage; ribbed design - for added strength; splitless snaps - less likely to snag, easier and quicker to install. Heavy duty gutter fasteners are primarily used to repair sagging gutters and low spots,as well as to re-enforce existing gutters. Ideal for straight or angled fascia boards. Fits all 5inch aluminum (non-plastic) gutters. Colour:Silver Material:Aluminum Size:5inch Package Contents: 50x Gutter hanger with pre-inserted screws Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.