APT / Ernst Mfg 8454 RD + 8457 BL Socket BOSS High-Density Trays w/ (4) &frac12;" Rail Set Transportable / Secure / Versatile -- Holds 30 sockets / Unlimited configurations options each TWIST on -TWIST off - TWIST LOCK DURA-PRO Socket Clips are easily positionable and can be installed between previously placed clips 2 Red + 2 Blue Universal Socket Rail 18" Long [Tray 19.63 x 3.63 x 1" (L x W x H)] 30- " Drive Socket Twist Lock Clips each -- 4 Sets (192) SAE & Metric Socket I.D. Stickers Fuel and solvent resistant -- Eco-friendly recycled products -- American Engineered and Made in the USA -- A "must have" for your toolbox