Amazon has Gedore 1/4″ Square to 1/4″ Hex Bit Adaptor (1649329, 620) on sale for $4.75. Shipping is free with Prime or orders $35+.

About this Item:

• Practical bit adapter for using a hex bit on a 1/4 “”square ratchet, ideal for tightening screws with ratchets and torque wrenches
• Optimal fit for a secure hold and easy to change bits, with hexagon socket according to DIN 3126 – D 6.3 (1/4 “”), with square socket according to DIN 3120 – C 6.3 (1/4″”) / C 10 (3/8″”)
• Easy mounting of the adapter on ratchet thanks to the internal recess on all sides for locking the ball in the square
• Compatible with all common bits of different brands, perfect addition for every 1/4″” ratchet set, ideal for professional users and hobbyists
• Material: tool steel, Length: 25 mm, Width: 14 mm, Height: 14 mm, Weight: 20 g,
• Country of Origin: Germany