Give your jewelry creations a professionally finished look. Crimp covers are designed to cover up crimp beads or crimp tubes after they have been crimped on jewelry wire. Once applied, the crimp covers look like decorative beads. For best results, use the same size cover as your crimp bead or crimp tube.ncontains:n20 each of 3mm and 4mm smooth crimp covers. 20 each of 4mm sparkle and 4mm lined (scallop edge) crimp cover.