Safe and Effective: The flame-retardant shell provides safety and insulation during wire splicing; no cable twisting is needed. Connect wires securely without soldering or electrical tape; no tools required. The conical spring pulls the wires into the connector and screws on, ensuring a stable connection for wire pulling projects. Five Color-Coded: Includes five color-coded assortments of gray, blue, orange, yellow, and red connectors. Sorted sizes fit most electrical wiring projects and applications, making it a great addition to your electrical connector kit! Applications: The twist-on wire connectors are perfect for home theater, speaker wire, stereo wiring, automotive, marine, household, commercial, or residential applications, etc. Assortment Gauge: 50pcs Gray, min 2x#22 max 2x#16; 50pcs Blue, min 2x#22 max 3x#16; 50pcs Orange min 1x#18 and 1x#20 max 4x#16 and 1x#20; 18pcs Yellow min 2x#18 max 4x#16 and 1x#18; 12pcs Red min 2x#14 max 2x#10 and 2x#12, totaling 180pcs screw twist-on wire connector caps. Easy to Store: Our assortment of screw-on wire connectors is packaged in a divided storage box to keep the different wire connectors separate. Convenient for storage and use.