This Snapmatic module by Systematic Tools holds the Klein 9-in-1 Flip Socket set in Metric or SAE, 2 additional 1/4 hex slots to let you carry additional nut drivers to round out your kit to 10 total sizes. You can use any brand nut driver you'd like but I think the Neiko 20 piece kit is a great value. 

Around back is a magnetic slot to hold the short 2" Flip Socket adapter. Below that is a magnetic zone that lets you hold screws, nuts, and other ferromagnetic items to keep then handy. The bottom is open to make it easy to slide them out. The modules use powerful rare earth magnets to connect them together with a snap and internal magnets to hold the bits and rachet in place.

The module is designed to hold these tools:

• 4x Klein Flip Sockets
  • Metric: 7+8mm, 10+12mm, 13+14mm, 15+17mm
  • SAE: 1/4"+5/16", 3/8"+7/16", 1/2"+9/16"
• 2x ¼" nut drivers, your choice
• 2" Klein Flip Socket Adapter

Instructions for connector magnet and strike plate

• Source parts:
  • (1x) 60x10x3mm N52 magnet for side connector from JC Magnetics
  • (1x) 60x14x1mm strike plates from TotalElement
• Use 60-80 grit sandpaper to rough up surface deeply for glued sides (4-6 passes in two directions)
• Wipe surfaces with Acetone to clean
• Apply even surface of gel-style CA glue to pockets
• Place magnet or strike plate into pocket, clamp for 5 minutes
• Release clamp and allow it to cure for 24 hours before using

Instructions for internal magnets

• Source parts
  • (1x) 60x10x3mm N35 magnet for internal slot from Amazon (Loving)
  • (1x) 40x10x3mm N35 magnet for internal slot from Amazon (MIN CI)
• Attach the 60 and 40mm magnets together magnetically, they will be happy in one orientation
• Slide the magnets into the bottom slot with the 40mm end first
• This should be a snug friction fit, no need for glue but if loose apply a few dots of CA glue and let it cure for 12-24 hours before using

If friction fit it loose on rachet or extender, apply a tiny bit of blue tack to add friction. A little goes a long way.

Want more info? Visit the Systematic Tools website (sorry can't link here)