6PCS Shooting Archery Lighted Nock Compound Bow LED Lighted Red Arrow Nock (red) Diameter: For 6.2mm Shaft Fits any bolt with diameter 6.2MM Users could control turn on or turn off when they need. If you need the nocks lighted,then put the pin into nock,let's the the cathode contact each other. If you don't need it lighted, then just transfer the both end.it is very easy. same plastic color as the light Note: This is not a toy, do Not shoot at people