Wiss lightweight Quick-Clips feature stainless steel replaceable blades and blue PVC contoured handles:
#1570B has sharp points.
#1571B has blunt points.
#9328 is a pack of 10 pairs of sharp-point replacement blades and 40 screws for #1570B.
#9329 is a pack of 10 pairs of blunt-point replacement blades and 40 screws for #1571B.
Wiss cutlery steel thread clips are hot drop-forged, nickel plated, 4.75" overall with a 1" cut:
#TC-1 has sharp points.
#TC-5 has blunt points.
Wiss stainless steel /polymer composite thread clips are light and comfortable, and offer the unique feature of being sharpenable without disassembly:
#TN1 has sharp points.
Priced and sold each.