Products are carefully crafted 
i) infrared detector
ii) LCD display 
iii) model select (object or body) 
iv) down button 
v) up button 
vi) set/memory 
vii) measure button 
viii) battery compartment cover 

Completed with Precision Probe, Fever Alarm, LCD, Memory Array 

Battery Size : 'AAA' 1.5V x2