Please note this listing is for 4 PACKS / SETS. All products listed in packs are also available individually, please see our other listings or contact us. Solid zinc arm turns 90 to prevent sash opening. this product is face fix and us a simple and secure operation - the window can easily be opened from inside by turning the arm into the open position. Supplied with plastic covers and conceal screw fixings, and a compression adjustment supplied to suit a range of profile systems.Alias ID - bc08018x4