Seiko Presage SSA457J Instruction Manual page 54

B
B Type
While pressing the push buttons on both sides
1
of the flap, lift to open the clasp.
Push button
Remove the pin from the adjustment hole.
2
Slide the band left and right, and insert the pin
into the adjustment hole at an appropriate
length. Push the buckle and fasten the clasp.
Buckle
Adjustment hole
Pin
EN
2
49