These Are M10 threaded lamp nipple and they are hollow for threading cable. Item type: M10 1mm fine pitch threaded rod Nipple hollow tube. M10 Zinc Plated Hollow Threaded Rod Lamp Tube for DIY Light Fixtures.
PATIKIL M10 Fine Thread Brass Lamp Pipe Nipple, 5 Pcs 60mm/ 2.4" Length Hollow Tube Adapter Coupler Connector Pipe Fitting Hardware DIY Repair Part for Lamp Lights
4 pcs M10 Screw Lamp Finials - 0.8 Inch Copper Screw Finial for
10PCS RGB LED Strip Connectors 3 Pin with 20Pcs Connector Clips 10mm Wide RGB Splitter Right Angle Corner Connector Solderless Gapless Adapter for SMD 5050 LED Strips(5 PCS T Shape + 5 PCS L Shape)
10Pcs LED Strip Light Connectors, 10mm RGB LED Strip 4 Pin Connector Solderless Gapless Adapter 5 PCS T Shape and 5 PCS L Shape Universal Extension Wire Kits for High Density Waterproof Tape Lights
Switched lamp holder B22 large bayonet cap in 5 finishes M10 base thread
Switched lamp holder with matching open hook large bayonet 5 finishes M10 base