This cradle snugly fits the $18 ($9.99 on sale) Harbor Freight 3/8" variable speed, reversible, keyless chuck, 3,000 rpm, 3.2 amp (400 watt) drill. SKU numbers are 60614, 3670, 61719, 62856 and perhaps others through the years.
Works OK for light-duty sanding, grinding, wire brushing small parts. I used 3/8" x 1" bolts. Finger-tight is adequate.
The trigger has no speed-dial, but it has a universal motor. So I lock it at full speed, and use a $5 (600W) light dimmer for speed control.