This is Pane 5 in the PSB and contains two 2nd Class and two £1.00  Self Adhesive, Barcoded Machin Definitives with two central labels.  

The Machins have M22L + MPIL source code.  

According to pre-issue information provided by Royal Mail, printed in Litho by International Security Printers. 

The pane is supplied exactly as shown in the picture.

Single stamps from this pane are available on item number  314396767777