ER-A450 (serv.man5). ERA450 Operation Manual - Sharp ECR User Guide / Operation Manual. Page 126

For your register, the following options are available. 
For details, contact your dealer.

•RAM memory chip model ER-03RA
•Remote drawer model ER-05DW
•Till model ER-58CC and till cover model ER-03CV
•Coin case model ER-58CV
•EFT interface board model ER-01EF
•Key kit models

By using the following key kits, you can change the keyboard layout of your register including the
expansion of the number of departments.

ER-11KT7: 30  regular size key kits
ER-12KT7: 30  1 x 2 size key kits
ER-22KT7: 10  2 x 2 size key kits
ER-11DK7G: 30  regular size dummy key kits
ER-51DK7G: 10  5 x 1 size dummy key kits