A – Forend Plate

B – Latch bolt

C – Dead Bolt 

D – Screw Channel for Cylinder

E – Lockcase

F – Action-arm

G – Follower

H – Turning Device

I – Spring

J – Backset

K – Distance

L – Lockcase Width

M – Lockcase Height

N – Forend Length

O – Forend Width

P – Lockcase Thickness

Q – Forend Thickness