TierraCast® brass plated Britannia pewter 28mm round tribuckle for use with cording up to 1/2" wide. Great for multi-wrap strap designs! TierraCast Safety Compliance Info. To use, rivet or knot cord on smallest opening, then thread other end of cord through the wider openings. Keep the buckle's ridge on the top side of your design — it helps keep the strap in place once buckled.