Cheap chinese parts that are good for prototyping simple circuits, but not for production or permanent use. They have no datasheets or specs, and likely wouldn't meet them even if they had them. You know what you are getting when you pay this little for a huge set of parts. Don't expect miracles, and buy good parts from a reputable dealer if you are building or repairing something that you care about.
Streamline Your Prototyping Work With WayinTop Jumper Wire Kit - Preformed & Flexible Breadboard Jumper Wires With Tweezer Tool
7 Review
10 Pcs Copper Clad Laminate PCBs - 7X10 Cm 4X2.7 In - Universal Circuit Board For DIY Etching Projects
6 Review
10-Pack Double-Sided Copper Clad Laminate PCB Circuit Boards - Perfect For DIY Prototyping!
8 Review
20 Pcs Double Sided PCB Board Kit For DIY Soldering Projects Compatible With Arduino Kits
12 Review