Aluminum Standoff: 1/2" Length, 4-40 Thread, F-F (4-Pack)

Nylon Spacer: 2mm Length, 4mm OD, 2.7mm ID (50-Pack)

Nylon Spacer: 4mm Length, 4mm OD, 2.7mm ID (50-Pack)

Nylon Spacer: 6mm Length, 4mm OD, 2.7mm ID (50-Pack)

Nylon Spacer: 8mm Length, 4mm OD, 2.7mm ID (50-Pack)

Nylon Spacer: 10mm Length, 4mm OD, 2.7mm ID (25-Pack)

Nylon Spacer: 12mm Length, 4mm OD, 2.7mm ID (25-Pack)

Nylon Spacer: 15mm Length, 4mm OD, 2.7mm ID (25-Pack)

Nylon Spacer: 20mm Length, 4mm OD, 2.7mm ID (10-Pack)

Nylon Spacer: 25mm Length, 4mm OD, 2.7mm ID (10-Pack)

Motor with 25 mm diameter and 48 mm length, 4,4:1 metal gear, 6 V  operating voltage, 0,05 A to 2,4 A power consumption, 1300 RPM speed and 0,6 maximum torque. Pololu 1581

Motor with 25 mm diameter and 48 mm length, 4,4:1 metal gear, 6 V  operating voltage, 0,275 A to 6,5 A power consumption, 2150 RPM speed and 1,5 maximum torque. Pololu 1570