Concrete Post Clip, all steel construction finished in black powder coating to fit 4inch, 10cm (H) section concrete posts No drilling screwing or fixing involved. Simply slide the bracket over the top of the fence post and position in place. for 2016 we have now upgraded the post clip to incorporate a screw fitting to hang the grow bags from. This design allows you to place the post clip over the post then turn the screw until clamped to the post. Happy growing. We advise using wd40 or similar on the screw part to stop rusting as this being threaded can not be powder coated.Small amount of grease could also be used. For hanging grow bags, half moon baskets, hose pipe reels etc. Slight color difference or difference Colour:Black Material:Metal Package Contents: 2x concrete column clip Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.