Pololu - Aluminum Standoff: 3/4 Length, 4-40 Thread, M-F (4-Pack)

These hexagonal male-female aluminum standoffs keep parts spaced 0.75" (19 mm) apart and are great for building a multi-level robot chassis. Both ends of these 3/16"-wide standoffs have 4-40 threads. The standoffs are sold in packs of 4.
These hexagonal male-female aluminum standoffs keep parts spaced 0.75 (19 mm) apart and are great for building a multi-level robot chassis. Both ends of these 3/16-wide standoffs have 4-40 threads. The standoffs are sold in packs of 4.

Aluminum Standoff for Raspberry Pi: 11mm Length, 4mm M2.5 Thread, M-F (4- Pack)

F13: Line Following Robot - Embedded Systems Learning Academy

Aluminium Stand-off / Spacer Range - Proto-PIC

Aluminium Stand-off / Spacer Range - Proto-PIC

F13: Line Following Robot - Embedded Systems Learning Academy

M3 x 4mm+6mm Hex Male-Female Standoffs,Male Thread Length 6mm,Brass,Pack 50-Piece: : Industrial & Scientific

Pololu - Aluminum Standoff for Raspberry Pi: 11mm Length, 4mm M2.5 Thread, M-F (4-Pack)

Pololu - Claire's dead reckoning robot

These 3/16-long hexagonal female-female aluminum standoffs keep parts spaced 0.188 inches (4.8 mm) apart. They are like elongated, 3/16″-wide hex

Aluminum Standoff: 3/16 Length, 4-40 Thread, F-F (4-Pack)

Pololu - Aluminum Standoff 1.25 x 0.25 4-40 M-F 4-Pack

Aluminum Standoff: 3/8 Length, 4-40 Thread, M-F (4-Pack) at MG Super Labs India