Olympic lockers

These are lockers used during the Olympics, with cheap Chinese keypad locks on.

They take 4xAAA batteries, or USB power, and have a reset push button of some sort on the inside.

Some of the locks are glued to the doors.

Casing

MODEL: SN-DJ500 PATENT NO.:200820095244.2

QA sticker is damaged.

Patent belongs to Shenzhen ZFD Industry Co., Ltd.

Chip is painted, but board has sticker on:

PW-206BHT-O
C316&A260_v102
P/N:0012 14298

P/N is reprinted variously around the board as S/N.